Im a big fan of diesels as most of you know already and I abuse them regularly....So Im a big fan of gen sets..
We have had one in our RV for 10 years..3800 hrs never misses a beat..have one in the boat..love it, time will tell rather it will take the same abuse I give all my diesels or not.
I passed up on a like new 6KW with 250 hours on it a couple years ago for 2700.00 as I just didn't really need it...it was a take out from one of our local fire departments trucks...
Keep your eyes and ears open..use a little imagination and scrounging ability...you can find decent gen sets for allot cheaper then you think...so its not the end of the world if one goes belly up either...shoot I just might rip mine out of the RV and stick it in the boat if I need a replacement...probably worth as much as the whole darn RV in this market..
To me the only reason to not have a gen set is the size of your boat..It doesn't make much sense in a sub 30 footer but once you hit 36 plus the room is there in most of them and the advantages as well.
Go for it !