This seems to be a common topic at the moment, you know, the last generation high end card versus the newer generation mid range card, there is of course no clear and correct answer, both have key attributes in their favour, if you will forgive me for my laziness I am gonna paste what my views were in a recent other thread, I think as an 850xt owner I was being fairly honest and diplomatic (albeit just a little biased!) it goes like this:
"You are posing yourself the problem everyone faces on a tight budget, do you go for the more upto date current mid range card with SM3.0 or opt for a high end previous generation card without SM3.0? Only you can really answer that and we all have differing opinions most of which are valid to some degree.
I had a 6800 with SM3.0 prior to my non SM3.0 current card, the 6800 was good, in BF2 I could however only manage mid range visual settings with little or no AA/AF but I had my nice lights and additional effects, now with my 850xt running far in excess of PE speeds I dont get the SM3.0, what I do get though is maxed settings with loads of AA/AF and lets be clear here for one minute.....both visually and gameplay wise there is no comparison the 850 without SM3.0 wins hands down! Fact (IMO).
Now that only applies if you are playing the most demanding games where a 1600xt (or in this case 7600GT) for example just has not got the processing power of the 850xt, I would imagine in CSS or DoD the 1600xt (or 7600GT) would be lovely and give you that SM3.0, these 2 games actually support dynamic lighting in SM2.0 so you get some of the quality as well from the 850. The 1600xt and 7600GT are excellent value for money cards and it is more future proof but I feel today in demanding games there is little point in having the SM3.0 if your resolution and/or display settings are mediocre cause you just dont have the revs to run it smoothly. I got a 32FPS increase in DoD when I got the 850 over the 6800 and 21FPS in BF2, whatever game your playing, if you cant keep the framerate above 30FPS the experience is going to be shallow. I have not missed SM3.0 in the slightest! But hey, thats my opinion".