John D Davis wrote on 6/4/2011 1:57 PM:

I have owned both and both are:

Scared of Oil!

Boomerangs off the Dry!!

and Very Unpredictable!!!

 

I know you probably already have your mind on getting one or the other. So Id go with the one thats the most appealing to you. There may be a difference in reaction between the two, but its really not enough to research and ask people opinions of them. I personally liked the 505A better but they are both very pacific lane condition balls,etc. Good luck with your decision and one note: DONT BE AFFRAID to change the OOB surface! John

John D Davis wrote on 6/5/2011 8:55 AM:

Hey Killpins, I have used all the balls you have been throwing personally, so I can say what I am fixing to say about them. The 505A and 607A are stronger off the spot then almost anything Lane 1 and Lane Masters have to offer,etc.

 

Thats being said I wouldn't get either of them simply because they may be uncontrollable for you period. If I were you, I would try maybe a bigger core such as the 930A or 920T for they will give you a better feel and somewhat resemble some of your recent balls... With the right layouts, the high performance balls will be the ticket for dry lanes, etc. I had a 920T that was 5-6 inches away from my PAP and that ball went forever before it rolled up! Some of these people on here, jump on here and say oh yeah thats a great choice,etc. When they really don't have a clue, for they just know that they LOVE some track balls! After 6 months or more of throwing track with a handful of choices then I would purchase one of those balls you are asking about. For one, they are in fact great in cirtain places, and two, for you will be more familiar with that nice movement off the spot track has to offer....

 

Good luck with your purchase. Maybe you will take in to consideration on just some of the things I have said. It would be nice if someone aggreed with some of the things I have said. John

Out of curiosity, since the coverstock is the tire and the core is the engine, can I rightly assume that the 9 series cores responds more smoother/ less erratic off the dry than the 5 series or 6 series?

Well I'm going to give you my input again, take it if you want or not that's fine. 

I don't think the 9 Series balls are going to give you what you are looking for especially if you have issues getting the ball down the lane or speed control issues. If you drilled one with something like 6" pin you have now drilled a lane condition specific ball that may work well when it does work but probably won’t work as much as you want. Unless you have a 6 or 8 ball arsenal I would tend to not drill a specific piece like that.  

The 5 series balls and 3 series balls and even the 607A SE are the most forgiving balls in the entire line. (granted you have the proper layout and surface) The closer a ball is to Symetrical core shape the more forgiving its going to be in general. Is it going to give you the most pop or hardest hit? Maybe not but you aren't saying you are having trouble carrying, you are looking for a more angular reaction and by the balls you are stating something to use on a THS or broken down Challenge/Sport condition. The more forgiving core shape will allow you to make smaller moves to stay in the pocket longer. You can tweak any TRACK ball’s cover to match the volume or surface. The ‘A’ balls even with surface still maintain the angular backend shape just a touch earlier read depending on the surface. I have played with surfaces on every ball we have released in the last 3 years and drilled multiple balls of each kind for myself and have used them extensively. Everyone has an opinion.

Bottom Line: If you were in my area I would take you out on the lanes and watch you bowl on the patterns you are referencing and make a judgement from there. I would Highly recommend you go see a reputable pro shop in your area and have him do just that. If he can’t be bothered find one that wants your business and will invest the time in you as their customer.