As long as the kids are not too tall the middle row seat should be plenty comfrotable enough (can't speak for the rear seats). It's only when you get up over 5' tall that the high seat position can be irritating with the roof line right about eye height. The raised seat is GREAT for smaller kids though. At just over 6' I don't find the middle seat uncomfortable just a pain to see out from. Make sure you check the middle row seat supports as there are a couple of us here that have the support brackets in the wrong position so they don't even support the seat. It seems that Land Rover Australia completely failed to pick this up even though the seats and seatbelts all have to pass ADR when they come into the country.
As for towing, the Defender is very low geared so is not quick off the mark anyway. With a caravan or trailer up to any resonable size you can sometimes forget it's even there.

