There seem to be two motivations for a power supply modification.

Some people are fed up with the unreliability of the SMPS - predominantly in the G-series, I think? Meridian have got something wrong, and a clean sheet design may be a good way to get a reliable supply. I don't think I've ever had any PSU fail on me, and its not something I lose sleep over. The ECM40UT31 is so cheap and readily available as to be disposable.

However, if I'd had a PSU fault that actually damaged the controller, I expect I'd have a very different attitude. I'd probably want to find a more reliable solution - as long as it didn't add more problems than it solved.

My motivation has been quite different - it's purely sound quality; I've been convinced for some time that SMPS are bad. And bad for digital circuits as well - not just analogue circuits. When a little research showed how commonplace, and how bad, the stock SMPS are, it made the effort and the risks seems worthwhile. So if it's possible to fit an LPS for less than Meridian charge for an SMPS - and get better SQ and better reliability into the bargain - why not?

Of course, I can't prove that LPS are more reliable than SMPS, but they really are pretty simple, and the common designs have been around for a LONG time. It's not proof, but I think it's a pretty good indicator of a mature design that's had all the common pitfalls developed out. The better supplies also have lots of nice-to-haves, like adjustable outputs, over-voltage protection, remote sensing, battleship engineering, etc. In other words, the sort of things that help to look after the equipment, and not just protect the power supply itself.

Nick