the all-alloy bonded bikes were much more solid than the alloy-lugged carbon bikes...alan and vitus were pretty much the the only players, though they were rebranded a bunch (guerciotti, tomasso, others i'm sure).

big difference was the adhesive. the alloy bikes could be oven-cured at higher temps, so they used different glue. the carbon ones used a lower temp (and less strong) version, and were notorious for failing after being left in a hot car (for real).

i had a vitus carbone 7 for a while. light, cool, flexy, and ultimately too big for me. in small sizes with low-power/light riders, they were great bikes. my 5'0" / 95lb girlfriend had one, and it was like 17lbs in the late 80s (built with superbe pro and gel 280s)! but in real man-sizes, the small diameter alloy tubes were ridiculously soft. (though the hard-man sprinter sean kelly rode vitus for years).

the early specialized bonded carbon bikes were much more solid in my experience. i had a 2nd gen version with slightly oversized tubes (still bonded) that was a fantastic ride.