If it's full height, logain I'd agree with you. Low profile, the HD7750 is it, as long as it remains available. For the latest low profile offerings to be weaker than that one, yet it might go away, does not make any sense.
I have played GW2 at 1600x900 with a variety of cards, including the HD6670, HD7750 (I'd bought them, so they were both GDDR5), and HD7770. The HD6670 was only "sufferable;" jittery on almost all Low settings and some better settings not even available. The HD7750 was actually decent (mix of medium and high), although a little jittery too. The HD7770 was mostly smooth on high to ultra settings.