not sure about 150 or 650, but I have ty 320. if you like TY then 320 is a step up in refinement.
BUT, if you want better focus ie hear things effortlessly (you mention "lots of people talking" things) then you might want to consider Toneking / MrZ Tomahawak or Ting. I don't own Ting but with Tomahawk it passed the Chesky's "Counting" track in You're Surrounded album. you can track who's who / where and who's not counting properly or making gibberish sound.
with metal or fast track tomahawk will be more effortless than my TY320. 320 has very very good bass and energetic tone but sometimes the bigger bass or intense attack will overpower some frequency. Tomahawk have slightly less bass and don't reach lower or tighter as TY but to my ear they're adequate and in some way fuller than monk+. the highs also not very clean but not splashy either. the faster or busier the track the more I'm in awe with Tomahawk. and it's just 32ohm, perfectly fine with most portables.
However you might consider some of it's shortcomings. in my case: thicker shell. not much fit but YMMV. cable stiff (maybe just my version). sound might be too forward. You can hear effortlessly but you also might confuse about the headstage, but in my case that's the way it is.
ignore the stage and just pick any instrument you want to hear, rewind and you can pick another instrument to focus, if thats your thing
just IMHO
edit
after writing this, just for sanity check, I pull out my tomahawk, put VE foams and listen to SOAD, Mars Volta and Arctic Monkey.. superb. what I write above, stands.