I have owned two out of the three headphones listed. I have briefly heard the 650s a while ago but cannot really comment on them aside from comfort (very close to DT-880 but i think Beyer has the comfiest headphones ever, great build quality too). HE-400s like Whitetriton said, can be incredibly sibilant, at least in my opinion. The DT-880s are also a very bright headphone, from comments and personal experience. I always EQ'd mine down a lot, but not as much as the 400's. I sold my Hifimans also.
*Btw I can't say what these headphones would sound like through different amps, I am currently using a Xonar STX sound card, may add brightness and different sound overall I don't know for sure.
You said you were looking for enhanced detail and soundstage, but not so fatiguing (I'd say HE-400 may have slightly better detail and soundstage, but can easily be fatiguing. DT-880s are a little smoother sounding and more neutral, decently dropped bass, and slightly dropped highs.)
Also you said you want the extended bass, The DT-880's do a fine job of reaching low, but I will say it is subtle, HE-400's win here.
Lastly you asked for quality and reliable build (not to mention the comfort) I say DT-880's win here. HE-400's seem legitimate on build don't get me wrong, but I love the sturdiness and feel of the DT-880's, compared to the arguably fragile feel of the 400's.
In the end, I say you look for some DT-880's if you aren't afraid of some true natural sound. As Whitetriton said, probably best value. I say DEFINITELY best value, at around $200, I'd say its a way safer choice than any other option.
Sorry I cannot comment more on the 650's someday I need to get more familiar with the sennheisers, all I own are the HD-280's.