In my experience, Russ Andrews products are good. And they have a trial period - there's a few things over the years that I've tried out and ended up sending back, without issue. Good quality power can make a huge difference, but only if everything else in the system is at a good standard, otherwise it will still make a difference, just not that noticable. Also bear in mind that sometimes these kind of upgrades can change your system sound in a way that you don't actually like (mainly if it unmasks some other issue). It is therefore best to try before buying, or buy second hand at a good price that will give you the option to resell it at little or no loss if it doesn't work out.
Anyway, regardless of which upgrade, my general advice would be to only do this kind of upgrade if you are really sure that you will be keeping the main component for a long time; otherwise when you upgrade the phono stage, the power upgrade will become redundant. Upgrades are a hard sell on the used market. Of course it's different with something like a power cable which you can just use with the next or any component