I have a Mausingfield. I am a CRF junkie. I like being able to launch spent brass into the next county, or plop it into my off hand depending on how I cycle the bolt. I like that the bolt stop doesn't beat up the bolt lug during aggressive cycling. I like the amount of purchase the extractor has on the rim of the case. I like that the necks of my brass don't get dented from being smacked into the side of the receiver from the ejector once the brass clears the chamber.
That being said, the Mausingfield is a very nice action. All of the parts are beautifully machined and it is a very burly action. The scope rail's engagement with the receiver is very solid and does allow for variations in the amount of cant while maintaining the rigidity of an action with an integral rail. I don't have an opinion on the toroidal lugs.
The action is very smooth and very fast. I am not a very serious "tactical competition" shooter, but the bolt can be cycled efficiently in a variety of shooter positions. I think as these competitions become more and more geared toward awkward shooting positions it might really begin to shine. Mine is the "105/5" cocking option and it picks up the round from the magazine and the bolt nearly falls into battery. The bolt knob is a hideous thing, but it works great for me because I lift the bolt with my index finger while making a loose fist and then close it with my thumb. Form follows function here I guess. This action is really fun to cycle.
All that said, my $550 FN SPR actions offer many of the same features...with a far better safety in my opinion.
I imagine that this type of an action doesn't lend itself to being a Benchrest accuracy type action. The bolt doesn't fit snug in the raceway like a Deviant. I've not been able to get mine to consistently shoot under about 0.35 MOA. But is is almost always under 0.6 MOA. I do think it has a niche market for the PRS guys.
I think I was oversold on it a bit and bought into the hype. I was really excited to see a CRF custom action. I don't regret the purchase, however. There are just some features I won't use; like the interchangeable bolt head and the barrel nut option.
This is all just my $0.02. I'm pretty much a nobody.