Need help on deciding on a TV for our workout room. Keep old 'good' LCD or replace

[biosci]

I was hoping I could get some insight from you guys. We want to get and wall mount a TV in our workout room. We have an older 40" Sony KDL-40XBR2 which was the top of the line set in 2007 or 8. It's a bit thicker than most tvs now and runs a bit warmer which I don't like since I don't want the room to be any warmer! But we can use that set or get a cheap set like a Vizio 39" for under $400. All we need is an HDMI in for an AppleTV. Would you guys keep the XBR set or just swap it out with the newer but cheaper Vizio?

The XBR2 Model we have..
http://www.crutchfield.com/S-NWHTLgJ...ml#details-tab

The Vizio we were looking at..
39" E390-A1
http://store.vizio.com/led-lcd-hdtvs/e390a1.html

I just didn't know if Cheaper tech from today is better than best tech 'back then'.

The Sony set weighs around 60+ lbs and the vizio only weighs about 20lbs!
I'm sure other specs may be better as well on the Vizio...
Should I give the Sony away?