♦ no "bring unread to top" function. i have enough trouble losing emails into the vast back-log of gmail without getting a torrent of livejournal comments burying them even further back. this has been a minor complaint of mine for some time-- presumably some day it will be fixed by google, but till then...
♦ imperfect threading. since the "sender" name is "username -- lj comment," which is itself fairly long, there is no "sender" blurb in the name chain: every comment looks like it has been left by the person initiating the commenting on the post. not a heart-breaker, but not ideal, either. since threading is, i think, a much more crucial feature of gmail than massive storage space, this is another strike.
♦ for some reason, gmail opens each reply to a comment in a new tab; the other webmail i was using opens each comment in the same tab. call me crazy, but i like keeping the tab clutter down, especially since it is so easy for it to get out of hand. another peeve!
♦ using a seperate email address creates a new "mailbox" that allows me to deal with lj comments at my leisure instead of bringing them to my attention immediately. there may be a force-redirect command that would fix this problem (& the first), but i don't know it. just having a separate space is nice. nothing condemning, but enough to make me want to keep using a junk drawer for the comments, in the end.