Bristol_Jonesey
It's strange, we have an APC Smart UPS 1500 protecting our server at work, and it's as noisy as hell!!
I can hear it from 3 rooms away, albeit when all other machines are switched off, but you couldn't record in the same room as this thing.

http://forums.apc.com/thread/3899
 
My servers plus cooling are helicopter like, I think power UPS producer do not care about noise of that reason... I wish you find some "music care" one

I have an older APC Back-ups RS 1500 and it does not make any noise at all unless the power goes out. Then it does beep but you can turn that off. It will keep my laptop, router, & cable modem up for a solid hour + when I lose power.

I owned an APC a few years ago that was very quiet - I kept it in my home studio room and the computer fans were a bigger noise problem than the APC. 
 
In server rooms where I have worked, the UPS units there were always much noisier than the unit I had at home, even units with comparable power. I would bet that there are still some units that are quieter than others.
 
When I setup my APC unit I tested the switch-over time - I never had a computer re-boot or lose data during the switch-over, but I imagine that some units are better at this than others.  

This model:
 
http://www.apc.com/products/resource/include/techspec_index.cfm?base_sku=BR1200GI&tab=models
  
"Audible noise at 1 meter from surface of unit 45dBA"
 
If this is located behind my desk, do you reckon I can get away with that level of noise?

I have owned noisy and quiet APC units. My current unit is an older very quiet XS 1300. Never installed the monitoring software because I do not like to install unnecessary background programs. The front panel of the UPS has all the info in a small display. The PC is never unattended so there is no need for automatic shutdown. IMO, automatic shutdown is more for unattended servers.

I agree Steve.
 
My sole concern is to protect the computer + ancillary equipment while I'm using it. It will always be switched off at the end of a session

The only concern I would have about tucking a UPS under desk is the same concern about a CPU...heat buildup. UPS devices can cast off a fair amount of heat which may not be a problem at your latitude but in mine used to cause the fan to cycle on high on an older unit. This was noisy and affected battery life.

I didn't know that any of them have fans.. This is the Cyberpower I have:
http://www.cyberpowersystems.com/products/ups-systems/intelligent-lcd-ups/CP1500AVRLCD.html
It either has no fan, rarely spins, I'm losing my memory, or I'm going deaf because I haven't noticed any noise at all. Same with my APCs:
http://www.apc.com/resour...ex.cfm?base_sku=be500u
That page says noise is 40db at 1 meter. One is sitting here silently on the floor beside me and is cool to the touch.

I have numerous APC units  - all very quite (like silent) and all very reliable - had to replace the odd battery over the years but that's to be expected.
I also have another UPS in an office environment - I'm not near there at the moment but that has a fan and is noisy as hell! Can't remember the make unfortunately.
So I would say any non fan less model but for me it's APC every time
Nigel
 

Ok guys, thanks to everyone for your input, I think I know which one I'm going for - yes it's an APC!!