With the Superlite and Kimber I've been shooting recently Ive found the slim barrel heating thing is a bit overstated.
The reason the two I've had ""opened up" are its very difficult to remain consistent over 9 or ten rounds. I didn't try it so much with the Superlite, but the Kimber will literally stack them in one hole "sometimes" for 9 shots, other times I get fliers. I've got enough 9 shot (3 mags of 3 rounds) groups from it now to see a clear pattern, only about 1/3 of the time can I do my bit.
The VERY important take home from this is you need to be very practiced with these light rifles to get good results from them wether hunting or on the range.