Yup; each of us perceives comfort in our own personal way. My two main sets of phones are HD600 and MS2i, and I find them to be be sonically similar in comfort(remembering that the MS2i are weighted toward the rock end of the spectrum while the HD600 is happier to the "Classical" side)and also quite similar in physical comfort. I have just as many Ooohs and Boos with either set after about the same amount of wearing time.
....at least with my ears.
The HD600 are said by many to have too tight a clamp. The HD650 is tighter yet! But the Grados have an infinetly adjustable headband that can be bent again and again for a pefect fit.. The pads on the Senns are nice, but the Grado pads will, over time, soften up and conform to just "your" ears. It takes some time though, and although it's a bit daunting at first, there are miriad varieties of pads available allowing the listener, with a modest outlay of cash, the ability to fine tune the comfort and sonic levels of the beast. And even swap pads for different listening conditions if desired!
....I like reversed and modded 414s on my MS-1 but Bowl pads on my MS2i. I luv my HD600 dearly, but the pads they came with is the pads they come with!
But yeah; there are kinda two main camps here at Head-Fi: Grado; and....everybody else! The fact that Grado(and Grado/Alessandro)have such a massive and voiciferous following indicates to me that yup; Grado is nothing to be feared!