Hi Pete, thank you for your wishes; and for pointing out that I 'need' to start my own thread. Having now read and re-read this and other threads, I agree that it would not be very fruitful for me to post here again.
I also agree that many things can be causing the “my mac 10.8.3 freezing a lot” series of problems described by the OP [though I do not necessarily agree with the assumption that such problems would 'likely' be different to mine] - as well as those problems mentioned by three or four other guys posting here. And, yes, you are quite right about there being other threads [around the world] expressing 'similar' problems with OS X [10.8.3], not forgetting the 'Wifi' factor.
Per one of your other suggestions about how I might proceed, if I do find an issue with my 'own [beautiful little] machine', I will certainly be back in touch with Apple, from which esteemed manufacturer/supplier I purchased same, around three weeks ago.
With reference to you having five Macs, none of which having problems with OS X, congratulations! Had I realised that you had this to share, before submitting my first post, maybe I would not be humming “The Last Post” now 🙂.
Cheers, Dave.