A couple of examples from some old data in CG spreadsheets:
Raven1 with a pretty standard fit as I recall - 1475 lb (versus 1442 lb from website)
Raven2 with a night kit - 1520 lb (versus 1500lb from website)
From G-INFO, there are 310 R44s, of which 195 are Raven II (not accounting for deregistrations etc).
In very general terms (and if my memory serves me correctly), both the Raven and Raven II are pilot derated to 205bhp MCP.
For take off, the Raven II gains an additional 20bhp (245 bhp over the 225bhp for the Raven I).
AUW for the Raven II is 100lb better, but typically the aircraft weighs more.
The extra take off rating came in handy, but once in the cruise you were hauling a heavier aircraft around with only the same MCP available (admittedly this was not particularly noticeable).
You lose the problem of carburettor icing, but some people find starting a hot Raven II awkward - although I see one of the recent newsletters has some pointers on this. There are quite a few other differences, but that is the essence of it.
Last edited by longtime lurker; 23rd May 2010 at 19:45.
Reason: Added information