There's a few reasons. The first being the cord. On the dewalt kit it detaches from the body of the router. Very useful when changing bits and underrated until you actually change bits 15 or so times in one day.
It also comes with clear sub-bases that are sized for porter cable style bushings. These are very common and cheap. There is also an extra wide opening sub-base included too (2 1/2" opening I think).
The motor is shorter on the dewalt. This makes is more stable during use because of the lower center of gravity. It's not much taller on the Bosch at all though.
The handles are a bit more comfortable on the dewalt kit. They're rubber coated so your hands won't slip.
The plunge base is where the dewalt kit really shines. The plunging action is smoother, the dust collection is way better and it feels a bit more balanced.
The dewalt kit includes a very nice centering cone for centering the sub-base. Useful when using template guide bushings.
That about covers it. The bosch is a very nice kit too, so don't think you got the lesser of the two. I still have and love my bosch kit, it's just no longer my favorite. In fact, with the included accessories I'd likely grab the bosch at that price. I grabbed my dewalt kits when they were $150 each.
You'd be happy with either. You won't be disappointed with the Bosch kit.