I can't say I have noticed any sluggish behaviour; SSMS behaves just fine for the most part, it's just the initial load of data by the activity monitor that takes "forever" -- 3 min 45 sec just now.

Unfortunately, I haven't noticed any difference between my current 64-bit and previous 32-bit desktop. Nor does it seem to make any difference whether I am logged into the server or my desktop. Come to think of it, as I always remote desktop into the server, that last may not be true.

Richard