Duurty... I converted all but my Carrylite Mallards to waterkeel this year. For a foot soldier, its easy, takes a TON of weight off your back, and we usually don't hunt big enough water here in windy enough conditions for the water keel to matter as far as stability. I've hunted the GSL with all waterkeel dekes in absolute white capping windstorms this season and haven't had any tipper problems. Some areas, that might be the case but on your WMAs or big reservoirs, it shouldn't be a big deal. The only place I've seen that happen was on the east shore of Utah lake.... some of those waves have tipped my dekes, but thats it.
To do it... depends on what kind of dekes you have. What I did on my GHG to convert them from weighted to water is I just got a sharp pocket knife, cut the very back (including the glue cap to keep the sand in) and the very front of the keel off. That way, you still have a long, stable keel and since they're so big, there is a lot of water held in there to keep the deke upright. I have done this with Mallards, Gadwalls and some teal and let me tell ya, my back is thanking me for it. Good luck.... I sure wish they made some of the better looking dekes in water keel for us foot soldiers, but I'm sure we're not who the market is geared towards so it probably won't happen. 8)