I bought it to combat a severe over/under condition and to throw on an inside line on a reverse block. It didn't make sense to buy another resin ball for these purposes. I decided to try urethane and chose the Thunderflash because of its strong core.
Every review says this, and no one seems to believe it, so - one more time: get rid of the idea that Thunderflash is a weak ball. In a reasonable layout with box finish, it is a versatile medium oil ball. I can imagine how it would be a monster in an aggressive drilling. To quote the drill sheet: "Feel free to drill the Thunder Flash as you would any high flare potential ball. Use extreme caution when deciding where to place the weight hole - the Thunder Flash can flare up to 13 inches." I'm sure Storm intends this as a statement about high RG diff balls (2.565 RG, .055 RG diff in this case), but I wouldn't want call their bluff either.
While I'm thinking about it, the drill sheet is a model for other companies. Unlike Columbia's generic document, Storm makes a 6-page drill sheet specific to this ball. It presents 12 layouts, tells you how each of them will behave and makes some very specific suggestions how you'd apply them. Stuff like - Use one of these layouts if you have freshly stripped and heavily oiled lanes, or wet/dry conditions where you are forced to play an outside angle. Not everybody will need this information, but I really appreciated it. When your ball arrives, it might be a good idea to hold off drilling it for a day while you absorb this material.
Mine is 16#, 3.3oz top weight, 3" pinout. I had two very different jobs in mind, but the common theme was that I would take all the revs out of it and play the ball on a tight line around 3rd arrow. I wanted to pitch it out flat and let the coverstock and core do their thing. Therefore, I chose a 5 x 5, with the pin above the bridge and the CG out only fractionally about 3/8". With a weight hole, the statics came to 1/2 oz positive. The closest-looking thing in the drill sheets is their so-called "Warm Front Thunder" layout # 3. I shined it to 1200 after this proved stronger than I thought.
Thunderflash gives you a different look than pearl resin. It wants to be an early, strong, arcing ball, and it's a bad idea to attempt to make it into something else. If you absolutely must have a skid/snap ball, buy something else - you will not be happy with the TFlash. For me, it gives an arc/set/heavy roll reaction that is effective on many different conditions.
As long as it has some head oil to work with, it can be used on nearly anything up to medium oil. With dry heads, however, it will want to roll too early - put it away.
The single best thing about this ball, its real virtue, is that it is insensitive to the state of the backends. TFlash behaves very consistently through spotty, carrydown or flying backends. Whereas all the resin I own likes to be played only a certain way; i.e., only down and in, only swung, TFlash doesn't care about the angle of attack. In my experience, it produces an effective hit anywhere from 7 - 25. Mine seems exceptionally tolerant of high hits, carrying more trip-4s than anything else I own, yet leaves no more corners than my resin.
I would classify the hit and carry as very good, but not great. It is not as strong as the best resin, but stronger than any lightbulb core I've ever thrown.
I'm giving it a high 8. It's tough to reduce a unique piece of equipment like this to a single number. For the job it does, there are maybe two good choices and many bad ones. Here's how I break it out:
Control - 8. Despite its strength, a fairly controllable ball under a broad range of conditions.
Versatility - 9. Covers a great deal of ground, all the way from lightest to medium heavy oil, but must have head oil. At its best with inconsistent backends. A lot of different people could find it useful - down the boards, swing shot, strong layout and no hand, weak layout and much hand, a single ball for the minimalist and so forth.
Hit - 8. Tolerant of high hits, not quite as good as the best resin.
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Updated 3/12/2003:
After throwing Thunder Flash for 18 months, here are some additional thoughts.
I originally had it stacked over the bridge. When I was sure I wouldn't see that particular shot again, I redrilled it to 4 1/2 x 3 with a weight hole. The latter drilling is very strong, and probably preferable for a general purpose ball.
I have tried about every surface imaginable. You can make actually make a passable resin substitute out of it with a lot of polish. However, for me, the core lopes too much to be effective with as much skid/flip as it produces. My impression was that Storm designed this to balance the strong coverstock with a high-differential loping core. This style of core doesn't work for me in most other Storm balls, but it does with this one because of the strong surface.
My favorite surface on it is 800 grit. Depending on the situation, I may play it anywhere between 600 and 1000. I had reasonable success on a sport shot and a house shot on the same synthetic lanes at both 800 and 1000. I could get it to the pocket with either, but I think 800 carried better. While it's somewhat difficult to polish and resurface, it's a cinch to take down. So now, I keep an array of scotchbrite pads in the bag. n gloss in minutes.
Thunder Flash doesn't like me to hit it all that hard at the bottom of the swing. I thought for a while it was working best when I took a little something off it, but on further reflection, it's actually that my hand is relaxed, at the top of the swing, the release and the followthrough. It's a mistake to fight it by trying to make it rev early.
It's still my favorite ball on some, not all, difficult conditions. Despite the flare, it seemed a good choice on my two sport shots. If I were going to spend significant time on a light/medium sport shot again, I think I'd put a modest drill on one of my Thunder Flash Pros.
I can't truthfully say there's one specific condition it's made for. I like it pretty much anytime you have to be concerned with something overreacting to the dry, like maybe a hard wet dry you need to bounce off of, super-dry backends before they smooth out, shorter pattens in general, or a dry track area after several games. It can also handle a moderate amount of carrydown. I don't like it on longer oil, lots of carrydown or dry heads.
Several people have questioned the carry. I think the carry is somewhat spotty. In transition or carrydown, if I hit it hard at the bottom, or if I play a severe inside line, it may ping lots of 10s. But typically the reason you're throwing it is that it's so hard to get to the pocket, carry is a secondary concern.
