Definitely agree. Whereas Genesis were more concerned with legends, mythology and other abstract concepts (after Trick of the Tail I think this changed, with "Robbery, assault and battery" kind of pulling them into the here and now -- sort of!), Marillion were from the first rooted in the harsh realities of the workaday world, as tracks like "Chelsea Monday", "She chameleon" and of course "Forgotten sons" from their debut (and still best?) album, the phenomenal "Script for a jester's tear" show. Even when they started getting a little more abstract, around the time of their magnum opus, "Misplaced childhood", everything was still very much rooted in the reality of today. Fish's solo stuff (which I'm sure you have) also followed this theme, with songs like "Internal exile", "Credo", "Sunsets on empire" and the superlative "Plague of ghosts" carrying on, in one form, the "old" Marillion tradition.
Marillion then evolved, not into a pop or even a rock band, because despite the departure of their charismatic and multi-talented frontman, they were still the same band that Steve Hogarth joined, and again I point to "Brave" as being perhaps their next-best album, the worthy successor (finally) to "Script". A more powerful and emotional body of work you'll do well to find. If anything, Marillion threatened to "go mainstream" off the back of MC, with "Kayleigh" just missing out on a number one slot, and "Lavender" well up in the top ten, then it all sort of calmed down and they were left to create their music away from the harsh, false lights of the record charts, and have, I think, remained a better band for it. No-one's denying that those two tracks are great, but within the body of MC they are far from the best examples of Marillion's groundbreaking work.
I too had the jitters when Fish left: after all, he had been THE face of the band, and seemed to be (rightly or wrongly) perceived as the driving force behind Marillion. But when I heard the first tinkling strains of "The king of sunset town", track 1 on "Season's end", Marillion's first album post-Fish, I knew my fears had been groundless. With superb tracks like "Easter", "The space", "Berlin" and "After me" on that album, not to mention the soulful, heartbreaking title track, Marillion were back, albeit in a slightly different form, but still the band I had known and loved from 1982, when I first clapped disbelieving ears on "Market square heroes".
Since then, they have only gone from strength to strength, with albums like "Anaroknophobia", "Marillion.com", "Afraid of sunlight" and "Marbles" showing this band have a firm musical direction post-Fish, a somewhat new sound, and are without a doubt, built to last!
Compilation coming up, as soon as I get some dinner!
Watch this space....