Our center put in Twister pins about two seasons ago, this will be the third season. The first season, the averages across the leagues dropped at least 10 pins, some bowlers were down 20-25 pins. Honor scores dropped off to almost nothing. The main issue was the pins seemed almost dead compared to the wood pins they replaced so carry was down. The following season the averages came up a bit and there were a few honor scores. This season the Twisters seem like they are mixing much better and carry has gone up. Expect to see lower scores the first year or two.
Personally, I found that I had to hit the head pin a bit heavier than with the wood pins. I used to carry a lot of light hits with the wood pins and almost none with the new Twisters. After I made that adjustment, I was much closer to my average but still a bit down.