If the price is about the same, I'd say 28i for sure. I personally think the sport seats are much more comfortable than the regular seats. With the regular seats I feel like I'm going to slide off of it every time I take a turn.
Audi R8 V10, 6MT, Ibis White/Black with Red Contrast Stitching
Z4 sDrive35i, 7DCT, Alpine White/Coral Red [Retired]
335i Coupe, 6MT, Space Grey/Coral Red [Retired]