I am also considering an 850/940/740 purchase for my next additional Volvo. As a current 240 owner, I think I'll go with a 740/940 because I'm somewhat familiar with the B230f powerplant/drivetrain, and feel more comfortable with working with them than learning a new car/powerplant/drivetrain.

Additionally, all the FWD cars I have owned (VWs, Hondas, Subarus and Saabs), seem to need new CV boots every few years and that maintenance adds up if you can't do it yourself (I can't and it's $200 to $300 repair job). It's even more expensive if you have to replace a CV joint. Also, in my own personal experience FWD transmissions have been problematic. I have had new auto transmissions in my Dodge Caravan and Saab 900 which I attribute to design/manufacturing weaknesses. The Caravan's tranny went at 42K and the Saabs at 120K. The Honda tranny was replaced by the PO at 110K. I bought it with 120 K and it was still running strong at 180K.

If you check out cartalk.com, they have a car repair survey section:
http://cartalk.cars.com/Survey/Results/Repair-Costs/

that lists various Volvos versus all Volvos versus All vehicles. A quick check confirms the concensus here that older 850's cost more to maintain than a similar vintage 940. Keep in mind that the data is non scientific, but it is something to consider.

Tom