This post is a little long so I'll summarize up here. I had a great time, got some great coaching, and felt really good about my ball purchase that day. It was totally worth it and I'd like to go again next year when they do it again.
Update:
I went to the Demo. First thing they did was give me a free t-shirt. I got a ton of coupons including $20 off a new ball, $1 off towel, $1 off grip sack, and if I bought two balls I would get a free double tote ($39.99 value). Additionally there were at least a dozen balls with special Demo Day pricing and of course that included all the balls being Demoed. I had plans to use every one of those coupons so my $25 participation fee was already covered.
I got fitted for hand span and finger inserts and then they picked out a Columbia 300 Takedown for me.
You may have read earlier in this thread that I've never had a performance ball and didn't really know how to throw a hook. I thought I'd try what I used to do when goofing with a house ball, which is no thumb and spin it as hard as I could. That caused the Takedown to race off like a dragster to the left before reaching the pins. After a few throws experimenting like that one of the coaches approached me. I explained I was ignorant and appreciated her quick arrival. She told me to just throw it straight a little while and let the ball do the work. I threw it again and she stopped me. Now I needed to relax a little. I was used to having to put the death grip on a house ball and having to really muscle it down the lane. She said relax and let the ball do it's job. I tried that for a while and was doing okay but not seeing any real hook from the ball. She said to be sure to try a few of the demo balls before going home and went to help another bowler.
I threw the Takedown a few more minutes and then switched to the Ebonite Legacy. The Legacy was hitting a little bit harder but still no hook. I needed more advice and another Columbia 300 rep approached me. He explained how to let the ball fall off my hand a little earlier. I had a few embarrassing throws while I experimented with that and then I tried coming off the side of the ball instead of up the back and started seeing some hook from the ball but I kept hitting brooklyn side. He then asked which ball I liked better and told him maybe the Legacy but I couldn't really tell a difference. He said "follow me to the pro shop". We went inside and he added some surface to the Legacy. He said if I like what happens next then to pick one of the dull balls displayed on the wall. My next few throws were a breakthrough for me. I was finally getting what I wanted from a bowling ball. I hit 4 strikes in six frames, but after three in a row I checked the clock. I only had 25 minutes left. To confirm I wanted a dull ball I asked to switch balls again.
The Columbia 300 rep that helped me find that hook said he wanted to measure my span again first. His suspicion that my span was too small was correct, and then fitted me for a Crazy Antics. He told me it will be close to the scuffed Legacy but that I was likely to start hitting brooklyn side again. I then threw two brooklyn strikes, 9/, and another brooklyn strike. That rep was dead on! Time ran out and the guy next to me said he thought I through the Crazy Antics best but I told him I was most impressed with the scuffed Legacy.
I raced into the pro shop and declared my intent to buy a dull ball. The Columbia 300 rep was in there and explained to the pro shop guy what he'd done. The pro shop guy said, "We have several dull balls, but it would be too hard to tell you which to pick as your first ball". I understood that to mean 'just pick one'. I looked at their wall and was attracted to the red and blue of the Hammer Amp. It was $30 off for the demo day. I also chose a Ebonite Maxim for my spare ball. Paid a little extra to get the Hammer Two-ball Deluxe Tote because it was more than the $39.99 promotion for buying two balls that day.
So, I guess i'm now a Hammerhead and I should get my first chance to throw the Hammer Amp on Thursday night.