It sounds like he thinks 4th edition handled high level play the best of any of the versions.
The only other edition you could reasonably pick is the one that didn't go up to level 20.
That said Monte's latest article was extremely clueless. If I want to run an epic godslaying campaign of planar teleporting, I shouldn't have to roll 8 times the number of dice or tell my fighter types to go time out in the corner. All editions have both math problems and option bloat with the higher levels, fourth the least of them, but still enough that heroic became the only thing Wizards bothered supporting at some point. A big potential selling point for 5E would be to correct the math, but the way Monte is talking about it, it's not clear he sees the issue that needs correction.