I bought a CDI/72/hiCap/180/SBL Naim system all new, in the mid nineties and it gave excellent service for around 10 years. The end goal was that I wanted to 'activate' the SBL's, but the cost of doing so was prohibitively expensive at new Naim prices.
Ultimately though, AV came along and took my interest and buying habits in another direction.
I settled on some Sony ES 9000 series kit - DVD player and amp - for surround purposes, only to find down the track that on resolution, musicality and PRaT, the big Sony amp walked it all over the Naim electronics, which after about a year of sitting semi -idle, was all sold off.
It's definitely nicely made gear, and is a lot of fun to listen to in it's musical presentation - but it's also more about being 'impressive' than being accurate or neutral.
To answer the OP, personally, having owned it, I do feel it is somewhat overrated - there is quite a bit of a fanboy element to Naim owners, where apparently the only product worth having if you like music, is Naim -- which is patently untrue, - and the company itself makes similar claims re it's marketing spiel.
There is a certain cult like mystique about Naim which I'm sure the company is happy to cultivate, but in the real world it is marketing speak and little else.
As to value, i think that depends on whether you buy new or second hand, and in which market.
Having heard it, I would say the statement amplifier is the most overrated, overhyped, and poor value for money HiFi product that I've ever heard. Period.
That's not to say it's bad. Far from it - one of the best amplifiers I've yet to hear in fact. But at A$220,000.00?? One could buy a fully specced brand new E Class Benz and a 3 series BMW as a runabout for good measure at that price. And the system as a whole - Statement, Naim pre and streamer, and the then Ovator 600's was circa A$350,00.00 - that is the price of a brand new, four bedroom home + land in an outer Melbourne suburb.
And I didn't hear anything an A$10,000 Krell + a pair of B&W 800D's wouldn't do, at less than a third of the price.
So yes, whilst I enjoyed my time with Naim, having now heard a lot of different gear and moved on from Naim, whilst I think Naim is very good, I also think it is very overrated and overpriced relatively speaking to other products of equal quality, and equal or better musical satisfaction, available on the market for less cost.
Cheers