well this SMPS is most probably enough for your needs. Whoever saying it is not enough has very little knowledge about smps.
still follow this link and check ur actual requirements:
http://www.extreme.outervision.com/p...ulatorlite.jsp
Point no 1: If you have already bought the psu stick with it if you are not having stability problems. Look buddy Microteck is now something of a stellar performer but unless you don't add a graphics card or use heavy computing that will put your processor on 100% load for prolong periods, this PSU should do fine.
If you want to upgrade atleast get a zebronics 500W platinum if it's available. Zebronics is not a good brand but you can't help it as there is nothing else available.
If you are upgrading, keep in mind that at least 450W is must with minimum 30amps on +12V rails (very important). Even if a PSU is 600W but only have 20amps on +12V rails it's worthless. so keep this in mind. amps on +12V rails is very important.