I think if the members of Rush were to answer that question of what their eras were, they'd come back like this:
1. Early Rush - Pre-first album-Fly by Night - basically when their catalog of early bar-band songs were exhausted
2. Heavy Metal/Early Prog Era - CoS-Hemispheres
3. Pop Culture Aware Era - PeW-PowW
4. Synthpop/Adult Contempory Era - HYF-RtB
5. Modern Era - Counterparts-CA
For me, personally, it lines up more like your own.
1. Pre-Neil Rush
I find that since VT they feel that they are a "hard rock band" though they did some very progressive things, particularly on CA that harken back to the earlier prog eras. I think they have always had "prog moments" on all of their records, and those are either buried as in VT's case, or highlighted as in CA's case. I feel their worst studio album was Presto followed shortly by VT. When you look at the whole catalog, those stand out as the stinkers to me. Sure they had some decent songwriting on those albums, but it was the execution that failed. Presto stands out as a stinker due to it's overly slick production and weak guitar sound on a guitar-dominant album. VT stands out as a stinker due to the dated, layered, rap-style production. Nothing earthshattering here. No expert opinion, just a common one for many of us.