Brand image and market strengthbit-tech: Isn't it the case that PSU are mostly bought by brand, rather than the specific merits of an individual product?
Yea, well, I mean it depends. The majority just goes to a shop and goes "What power supply can I get for $20?" and that'll always be the case, but there will also be a big group that stays brand loyal from good service and warranty as well as product.
A whole history of PSUs right there
BT: Is the PSU market genuinely more competitive these days or has the same amount of companies entered the market that have dropped out?
I don't really think it's getting more competitive, but there are definitely more brands coming into the market. Some are doing well even - like some of those memory or graphics card brands - they are either lucky or know who to pick in terms of choice of supplier, so they are able to sell a cheap product of decent quality that competes with ours. Likewise there's also a bunch that have no idea and will never be a serious threat to our market share.
BT: Either customers or reviewers will root out the good from the bad then?
Yea, the users in many cases are quite educated and there are more and more becoming educated from websites and articles - word of mouth travels.
BT: What in your opinion, is the most important factor of a power supply?
There are the main features - it should definitely hold up to its spec: there's the ATX spec and also what the manufacturer wrote on the package, so the product should hold up to its promises. And then of course there are the features, but most of them are a matter of personal taste, such as like cable management and even the size of the fan. There's not a lot of difference between fans these days: everyone says '80mm is noisy, bigger is better' and it's just not true; we have calm 80mm fans and we have noisy 140mm fans. You can't really choose on size alone.
Really important features for consumers on power supplies today, from my point of view, are efficiency, acoustic noise and the technical aspects or voltage regulation and ripple. These are important aspects if you want to be happy for a long time with your product.