Having had VW vans for the last 16 years I can only give my impressions= :

Julio T wrote:
> What system is really the easier one to
> work on?  Also which system is the cheapest to
> maintain, cost of parts, etc...
While the age and condition of the van are paramount; the air cooled, = being simpler, is probably easier and cheaper to maintain. But remember: mai= ntenance history rules in used Vanagons.
>With those of you driving air-cooled vanagons, how are they in the<= BR> > winter?  Do they start up easy?
In my experience they were equal here; although the '81 GL did require= a replacement starter at about 80K and my '91 Caravelle is still on its ori= ginal at 156K.
> Does this happen with the fuel injected air-cooled engines? N= O.
>And last but not least, how does the heater system work in an air-c= ooled van?
 Think of how your Beetle heater worked and multiply the engine b= y 1.5 and the space by about five.
>Did all vans come with heat or is it an aftermarket thing?
Air cooled vans (pre-83.5) had a gasoline auxiallary heater a= s an option.
How well, fast does it heatthe van?  
IMHO the gas heater was sufficient and without it the van was cold and= I live in Southern Ohio where we  don't usually get  the real Mid= -West winters here.

I have seen the following advice on the list and would agree:  Buy the= latest and best maintained van you can afford.
--
Stephen Steele
'91 Caravelle