I am attempting to refinish a large portion of my basement and have gotten recommendations to use metal studs from a friend, but two estimates from contractors who recommend wood (treated where in contact with concrete floor). I have been advised that with wood that I can frame sections and install a plastic vapor barrier to the back of each section prior to nailing them up. But, if I use metal, can I still install a vapor barrier? Can framing with metal studs be done in sections, similar to wood? Have I been given the correct advise on framing in sections? Any help would be gratefully appreciated.

I would say stick with wood for this project. Simply it will be easier for you.
Rarely do we use metal unless it's a commercial job, this also complicates installing insulation and the vapor barrier if you go to metal for simple fastning reasons.
Here's what to do. Use a treated bottom plate, the rest can be regular wood, you need to keep the framing an 1" off the wall, after you've framed it, the insulation is next , use r 13 or r 15, for the walls, your ceiling is most likely already insulated from the first story floor joist, next is the vapor barrier. Use a 4mil platic and staple this with a slap stapler is best making sure the plastic is covering the whole frame, where you have outlets just cut the out the plastic in those areas only. Next is sheetrock or whatever wall covering you want,
One more thing its always best to seal the block walls before you do any of this, a good product to use is dryloc, get it from Lowe's or any paint store should sale this

As for you other question, you didn't get bad advise you just got different advise , you will have more people stirr you toward a wood frame than metal, metal is much harder to work with unless you've had experience with it, good luck