I must admit although I was doing a trade at the time and I couldn't make a direct A/B comparison between the two, bass response, in my opinion anyway, was not that much different between the M60's and my newer M80's. Once you get in to floor standing speakers of this size, I would suspect there is somewhat of a law of diminishing returns...
When I did an A/B comparison of the M60 and M80, the difference in bass in favour of the M80 was quite noticeable. I would imagine there is a law of diminishing returns.
As others have pointed out, with a sub, it becomes moot.
Edit: there was also a difference in the mids and treble between the two, though it was more subtle.
From what others have posted, there is a noticeable step up between the V2 and V3 in general.
Personally, I would love to hear the LFRs. I can't afford them, but it sounds like a completely different speaker in the sound stage it produces.