HASL isn't guaranteed to be flat, so with a component like a QFN, there's a chance that it'll sit at an angle to the PCB, and the pads along one or two edges won't solder when the board is reflowed.
Gold, silver or OSP finishes are perfectly flat, so coplanarity isn't a problem.
If you're hand soldering, then you should be OK either way. Personally I prefer gold finish for hand soldered PCBs because, if nothing else, the difference in colour makes it obvious which joints have been soldered and which haven't.