I like Tri-X at 1250 - 1600 is really pretty nice with daylight but more like 1000 with tungsten.
Plus-X was great in it 400-500. In fact I often preferred that to Tri-X at box speed in D76.
Now I use it for Tri- X when light is dim but not so dim as to need TMZ or D3200 at even higher speed.
I also use it for Pan-F+ which is a really nice combo. It gives a bit more effective speed than normal developers - I shoot it at EI 64 though, not 80 - and helps tame the highlight densities.