Well my personal view is that the RFA is better (though not necessarily easier). The atmosphere on board is much more relaxed than a warship - first names mainly. The only people not addressed as such by us lowly YOs are the Captain (sir), the Chief Engineer (Chief), the XO (ChOff), and the MEO (Second). On the bridge, and professionally, the Navs is Navs, and the Ops is Ops, but it's quite a chilled atmosphere.
The leave/work is the merchant navy way - 4 months on 2 months off up to 1st Officer (Lt. Cdr), then Chief Officers and above do 8 or 9 months on then 5 off. However, on very much means off - no going home every weekend and every night when not duty, and can quite possibly mean 4 months on say Orangeleaf in the Gulf, then next trip 4 months on Black Rover in the South Atlantic.
You aren't assigned to a ship as such until you become a grownup on 9 month trips (though they are making trials for repeat appointing), so you can go from ship to ship quite quickly, meaning you have to be able to pick things up from going from (say) a small fleet tanker to an LSL to a Fort AOR.
You also don't pay income tax if you spend 183 days in any 12 month period out of the country (which is why we don't like anchoring in UK waters as it loses tax days), which gives us a pay bonus (though pay is slightly less than the RN I believe).
There's a wonderful sweet spot in Lyme Bay which I'm sure you've all seen RFAs anchored in - it has the three T's as it were - Tax days (outside 12mile limit), TV picture, and Telephone signal.
We do also have to put up with:
1. Being the biggest target in the fleet, with everyone wanting to make is go bang.
2. Having those bloody orange lifeboats for people to aim at
3. Having a snowball's chance in hell of surviving if anything hits us
Discuss. Banter about lazy floating Tescos seems appropriate...