I'm not sure I agree with your arguments however ( are you surprised? )

To Hugh - to me - in a Lexicon parlance - classic might not mean what you suggest, but instead might suggest "a staple" - as in - a classic Lexicon Hall from 1985 is the same as a classic Lexicon Hall today; unless they explicitly indicate that such later Hall algorithms have been improved - and - they never say that. They add new algorithms for sure - but - they seem to stand by the term 'classic' as meaning - the best people expect form Lexicon. As for the argument that a 1985 algorithm might not stack up today - in my view Lexicon had essentially 'nailed' it to extraordinary quality by about 1980 - and why they became THE standard. In any case, if computational power were an issue, then it would be the likes of the MXP500 or MX400 wiping the floor with the likes of the 480L and PCM91 in that department, surely?
And to Arpengel - I think you raise "the great unknown" in all of this. I'm not convinced by the argument that just because Lexicon's reverbs are packaged in a PCM91 / 96 or similar - that they are better than in the MPX500. I'd wager, that where both such models are demanded to do the same "Reverb" - that they'd sound identical.
I just don't feel over the years that Lexicon could bring themselves to admit that for marketing reasons - but - by now they have lost their 'edge' - and it would be good for all of us concerned if better agreement was arrived at on that. At each price point - and that forced down every few years as computers become more dominant - I'd wager Lexicon's very best algorithms have been out into ever cheaper units like th MXP500 and MX400 - and that like for like named algorithms as might appear on the PCM range too, are just the same (surely?).
Overall - in my view - If Lexicon are using a "Classic Lexicon Hall" algorithm in a variety of hardware processors - from the 80s' onwards - then I'm assuming they put the computational power under the hood to execute that algorithm to its full fidelity, whether in an LXP15, PCM91, 480L or indeed MX400. I'm sure the editing detail is better on the more expensive units, but I just can't imagine why Lexicon would bother - or want to - call any given "classic Lexicon reverb algorithm"; the same thing across various hardware units, but actually execute it in an inferior way on some of them.
TC Electronic is slightly different - they branded their imrproved reverb algorithms with different names through the likes of the M5000/M2000 and on to the M3000 and Reverb 4000/6000 - so I don't think a like-for-like comparison is there.
Happy to stand corrected on all of this - but - I will buy an MX400 and compare it to my PCM91 and report back - eventually
