I was going to mention some of those, but Danny got there first I'm using a Profile on the rear, and true the engagement doesn't feel as 'direct' as a front freewheel would when I remember using one oh so long ago. Aside from what Danny said, by having FFW, there's also the plus side of: -no rear hub internals to faff about and service with, which can be pretty difficult -freewheel up front is the only thing needing service, but this tends to be less needed if you get me? ENOs, Tensiles, and ACS all seem to require less servicing when compared to a Profile or King hub. And even when you do service a freewheel, since everything is so much bigger inside, it does make life a bit easier with all the servicing. Don't Kings require some very specialised servicing with specialised tools? Freewheels just seem simpler to service generally speaking... there is of course the downside of the chain being on the move constantly. I think it looks quite nice in a way, some won't, but I think it's pretty nice and unique looking which baffles other genres of riders out there. But meh, point is, your chain is going to wear out much faster, especially if you cycle about a lot. For now, I say you should keep the King. Save yourself time, money, and hassle. But if you were to all of a build up a whole new bike, then go for FFW. It's up to you.