Marc, You already know I'm a Selmer fan.
They are really well built, generally. Although the youngest ones are now 30 yrs old so many have taken a lot of abuse ! I'd say they are generally better designed and built than old Marshalls, Laneys, Sound City's etc. They are on a build quality with early Carlsbro's and almost up to Hiwatt standard (although definately not as "beautiful" inside).
The earlier ones go for significantly more money (for "vintage" value I suppose). The later ones move from tube rectification to SS (which to my mind is an advantage). Also some of the earlier versions were "upside down", so all the heat of the tubes goes up into the chassis (like most combos). this is not as reliable a design as the later ones which have the tubes sitting upright, with the chassis underneath them - much better for heat distribution.
The last version (the SV ones) go for the least money .... about £200-£220 for a good one on ebay. They are still stuffed full of Partridge transformers, Mustard caps and (hopefully) nice old tubes. All Selmers are properly hand-wired too - no PCB's in sight.
The reverb on the SV's are a waste of time IMO. They are great amps to mod !!!