No. I was glad he left when he did, quite honestly.
Sticking just to their creative output,
if MM had to quit for some reason then I'd be cautiously happy about him coming back under the following conditions:
1) He isn't allowed to write or arrange vocals.
2) He isn't allowed to sing, narrate or otherwise vocalise in any way on record (backing vocals live are fine).
3) He isn't allowed to prescribe an overall direction for their albums but instead lets the other guys follow their collective muses.
Three out of the last four DT albums with MP are my three least favourite DT records and the evidence of ADToE suggests that what I didn't like about those records was, as suspected, largely down to the creative impulses of MP (although perhaps the next one will prove that theory wrong...).
There are elements to MP's character that I find irksome that I can't say I miss, but realistically they're not that important - I've bought the Winery Dogs album after all and I still buy Megadeth records despite the world class pillockry of Mustaine!