A raft with a rowing frame is not as easy to row as a drift boat (doesn't track as easily and takes more effort to manouver), not as easy to stand up and cast (even with a casting platform) and will get tossed around easily in the wind (not sure there is a big difference compared to a high side driftboat). Stores easier as you can just deflate & roll and break down the frame. Obviously a raft is better in class III rapids and greater (with an experienced operator) as that's a raft's primary purpose. Drift Boat is specific to fishing, raft is not, but does the job "OK". That being said, if I was given one or found one at a decent price I would probaly get it! Best to consider a quality manufacture (Aire) as opposed to a cheapo (Saturn). Materials and care will influence longevity. A good quality raft used specifically for fishing that is well taken care of can last up to 15 years (A raft used for White Water rafting, not as long - Commercial operators rotate their rafts every few years - after numerous repairs).
A fishing buddy has access to one and we take it out quite often, I have also been a WW rafting guide in Idaho. Consider something at least 12'.
P