Just put up a score of 1.6billion on the new code at my local arcade, my highest score before was around 400mil, this is on a machine where the slimer does not register at all. The other 5 or so games I played were average around 100mil or so, no better or worse then usual. The new code does make a big difference as it allows you to get that little bit further particularly on good games.
I didn't adjust my gameplay at all, just don't have the patience to time out modes. Would consider doing so in comp, if it provided a major strategy. Only real change to norm was focused a bit more on the librarian lader to get WCWKA, although skewed that multi ball up.
I will say by far the biggest improvement to the code is the add a ball on multiballs. It made the multiball a lot more fun and rewarding having that extra ball save time and additional balls (if you can get the scoop) it really helps ease the pain of all the cheap drains in other parts of the game. Also makes focusing on multiball more rewarding both from a points and playing perspective.
Not sure about modes being able to be timed out, like I said does not worry me as I wouldn't play that way. For torments I cannot see anyone leaving this feature on.
For me having the modes stay live after draining was a massive improvement due to the poor slimer on this particular machine (one of the original mechs that the operator has not changed over yet) before hand if you missed your skill shot you had f..kall way of getting modes started. The worst was you would get a mode going on skill shot then complete and drain off the first shot of the new mode. Which basically skewed you an lest you did skill shot again. On tables with a slimer that registers properly maybe not so big a deal.
All up I would rate the code a big step up. Yes it can be exploited by timing out modes, but hey you just cheating yourself. I can't really comment on any bugs, only playing in location I'm not that aware of the little issues.
Oh got the scream feature, very nice touch.