I have used my T8.1 on 12ies and the mag is good for 8 and a reload but the last few balls may be pushing it stock, I do not remember. The Tib seemed to point more natural for me but I have had the same feel with the glock real steel. I carry two extendo mags (17 rounds) and all balls have sufficient get up and go from a 12ie. With the Tib and the 12ie in the mag you should not need to change on the field with 4 or so mags you will be able to shoot 60+ rounds in a game with no changes. There is no doubt that the tib mags are more expensive and weigh alot more. I think the airless versions we kept hearing about are a unicorn. Either choice is a blast to play with.