The 74-80 comp is a decent representation of their early stuff. though it makes some weird choices (Finding My Way instead of Working Man is an odd pick for instance), but it represents the albums with enough tracks to get a sense of what they're like for you to get a sense of which ones you might want to listen to more of (if any). If you can't get into tracks like Xanadu and La Villa Strangiato then Rush's prog-era likely won't do much for you since those are two of their best from that period.
Rush's best stretch of albums is 1978-1985 imo (Hemispheres through Power Windows). Pretty much everyone who likes Signals also likes Grace Under Pressure, they're very similar in a lot of ways. That's less true with Power Windows since it amps up the 80s-production to the max which is a turn-off for some, but that's actually my favourite of the three so it obviously doesn't bother me.