I have the Phil & Teds E3 sport in red with the second seat and i LOVE it. It rolls smoothly over all kinds of surfaces, the front wheel pivots so turning is a breeze, both kids have plenty of room. my oldest is really tall, but he still fits comfortably. Both boys have ridden in both seats & i've never had a problem with one kicking the other, etc. i'm not really sure what the differences in the models are, except for colors... the only color we liked was the red one & that was only in the sport, so that's what we got.
there are two negatives we've found:
it does not fold up compactly. in order to fold it up & put it in the car you need to take the bottom seat off. and there's no latch to keep it closed while you are picking it up (there's a handle, but the stroller itself does not lock in the closed position)
it's not really recommended as a jogging stroller. the front wheel does have a locking pin, so you don't have to worry about stability, but the stroller is REALLY heavy. i think it's around 30 pounds BEFORE you put the kids in it. also, if you have long legs, or a long stride, you'll likely hit the bottom seat as you run... and there's nothing to protect the child on the bottom from the sun (or your sweat) . if you are a serious runner, i'd spend the $$ for a BOB and use a different stroller for everyday.