LOVE When Dream and Day Unite! All of the usual appreciation for the youthful energy and enthusiasm apply here, but above all I still think it's a fantastic collection of creative, varied and exciting metal songs. Obviously it doesn't sound as "mature" as I&W (funny to use that word for a sophomore effort) but I have always enjoyed it so much. The production is what it is, but it doesn't really bother me. And while the vocals can't touch prime JLB, they actually work ok for the songs.
I always thought that while I&W brought a bit of AOR influence in the progressive + metal mix (in the best possible way), WDADU was really the record where Rush were jamming with some of the more adventurous metal bands of the 80s, to come up with something quite unique. A Fortune in Lies and Killing Hand are probably my favorite (KH's version on Live at the Marquee probably even better - not so much, or not only, because of James' vocals, but thanks to Another Hand as the intro...). Ytse Jam is always a fun one, and I would agree with the Status Seeker's appreciation comments: such a cool intro and overall song. Interestingly enough, Only a Matter of Time was an early favorite, but I do find its busy vocal lines a bit much these days. Still like it, though. As I do the rest of "side B".
Bottom line - still a big fan!