the sony trinitron is a very good piece of hardware for its time. the reason why people say the image will look crappy is because of the decent difference in resolution. but at 480p you should be fine. i run dvd content through my 40" 1080p sony almost every night and while it certainly is subpar to hd content i have no complaints. especially when bluerays of the same content are $10 more. i can see why you wouldnt want HD_DTV!
in my opinion image quality doesnt start to get almost too horrible to watch until you drop under dvd-quality resolution. in any case what do you have to lose? if you dont like the tv you can give it to your friend after you tried it out.