MK...
A couple of points....
First, I shoot a Savage 210 with a 24" barrel and a 1-35 twist rate. The gun shoots exceptionally well with both Remington Core Lokt and Winchester Partition's, two of the fastest slugs on the market. This means that it is certainly possible to shoot these faster slugs in slower twist guns. However I do agree that in general a faster twist would be preferable.
Second, the Winchester Platinum Tips are not really great shooters out of most guns. While I am not sure why, they just aren't...
Third, if your shots are inside of 100 yds, the lightfields are all you will ever need. However, past 125 I could never justify shooting at live game with them. While I have yet to shoot at any deer past 100yds I want to be as reasonably certain as possible that I can make a clean kill, should the shot present itself in the future. For me, due to the Lightfelds trajectory, it simply does not fit that bill.