I don't have that exact combo, but the heads in all of the combos are the same.
I think generally the consensus is they're great heads, excellent sound and the CMD121P (what I have) is regularly recommended as the 'go to' one box solution. IME it sounds great, is an easy carry and certainly doesn't lack power.
That said, and my personal experience is, if the head *does* go wrong, it's likely an expensive fix indeed given the class D heads are very difficult to service. I've given an estimate of in excess of £200 for mine (before they saw it) by the UK service agent and I have seen others have higher quotes. Sadly the private vendor of mine never replied to my messages so I wasn't able to see if there was any warranty cover available, but that's part of the cost/benefit analysis when buying second hand.
I gather from what I have read on here and elsewhere MB Italy service is poor, though I haven't personally experienced that myself.
The good thing is that the LM form-factor heads are in effect interchangeable, so if it does go, you could always pick up a replacement second hand.
I've decided given lockdown meant I've not been playing much to go with a backup/alternative option for now, but I will try and get it fixed down the line.
If you're buying new then I'd say go for it - if second-hand, factor in that repairs might be costly, but I think I have been unlucky - faulty heads seem fairly few and far between.