Thanks for the replies.
Pretty much what I would expect Short Circuit, at ~£200 it is excellent value for money as you say. Have you pushed it to the higher end of its power dissipation capability? Does it feel like it will blow up?
Olsenn, could you comment on the PC communications for the IT8511? It would be very useful to setup a test waveform on the PC, download it to the load and have a scope syncronized to the output of the PSU under test.
Unfortunately high(er) voltage PSUs will frequently be tested, 140, 250V DC come to mind at a low current 1-10mA. The ARRAY 3710A quotes 2%+3mA accuracy in this range, so I will probably need a DMM too for current measurement if I am to have any confidence in it. From the Itech line the IT5812B can go up to 500V and the current accuracy quoted is 0.1mA (no further info is given on that figure).
The (looking on ebay) BEICH CH8710B looks like it is the same hardware as the ARRAY device, with a different screen. It can do up to 360V. There is also the M9712B that goes to 500V and seems similar to the Itech/BK unit, VFD screen etc. I cant make out what brand it is, here have a look if you can figure it out. It starts with an 'M'.
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?VISuperSize&item=130600015278 This goes for £477.
EDIT: Olsenn I am of the same philosophy too, but its not always black and white; budget is always a factor. Agilent and Kikusui also make electronic loads. No need to splash out when you can get the quality and specs you want a bit cheaper.
Lets see how much we can get the IT8512B for.