Personally, I'm fine with my SRH440s as most of the weight is centered on the top of my head, and they don't clamp too strongly. The only real problem I have is that they tend to get quite hot and itchy after a while, but that's to be expected anyways. And I wear glasses too - thick acetate frames, at that.
Still, comfort, like audio, is subjective. I think it depends on whether your ears are small enough to be fully enclosed by the earcups or not. Obviously if there's any ear between the pads and your head, the combined clamping force and weight of the headphones will be pretty uncomfortable, regardless of which circumaural headphones you're using. However, the pads of the 440s are quite stiff compared to other circumaural 'phones I've used. The SRH840s' pads, which are reportedly much softer, will probably go a long way towards alleviating this.