Overall, I like the debut, but I rarely listen to it, and whenever I think of the best debuts by any artist, this one never comes to mind. Some bands crushed it on their first album (Boston, LZ, VH, etc.), but I don't think Rush was one of them.
This is pretty much me. I think the debut sounds great, but I'll go a little further and say this: the fact it has the "Rush" name attached to it, somewhat paradoxically, hurts the way I assess it. In a vacuum, the album is musically very strong. But I can't help it - the "band" Rush to me really starts with Neil joining. It's not fully rational, I know. There's a lot on Fly By Night that could be from the debut (and, more broadly, CoS and 2112 still have traces of that general approach). And, surely, an album like Hold Your Fire is so much more far removed from, say, Hemispheres than FBN is from the debut, despite the musicians being the same people. Yet, to me, these are all "Rush" records in a way that, um, "Rush" isn't.
I don't think there's anything wrong with that point of view, at all. There are plenty of bands whose first release is sort of "separate" from the rest of the catalogue. Genesis started, for me, with Trespass. Dream Theater started, for me, with Images and Words. UFO started, for me, when Michael Schenker joined. So?
I know for me, not all of Neil's lyrics resonate with me, and I don't necessarily think he's the lyrical God that many do (still good, though), but with the exception of Best I Can (which could easily be on the first album) the lyrics from Fly By Night onward - even the ones from Geddy and Alex - are a real cut above, and that's the difference for me. I don't mind dumb lyrics - I'm a Kiss fan - but there has to be SOMETHING. (And for some reason, the line "tell you all my lies!" is so cliched as to be cringe-inducing).