What to look for in a good quality TRV?

[pototea]

I will shortly be getting some thermostatic valves fitted ot my radiators (bar the hallway where the thermostat will be) and am very confused with the many TRVs that are on the market.

I need to buy 10 & they seem to range from £5 - £20 in price but I am finding it hard to see why the big price difference and was hoping someone here could help.

Looking at the Screwfix website:

http://www.screwfix.com/cats/102636/Plumbing/Radiator-Valves

Eg
£5
http://www.screwfix.com/app/sfd/cat/pro.jsp?cId=102636&ts=83733&id=81179
I saw it in B&Q yesterday. It has a liquid sensor, temperature range of 6-32'C

Or there is this one:

http://www.screwfix.com/app/sfd/cat/pro.jsp?cId=102636&ts=83948&id=25900
£10
Drayton RT212 with a wax sensor, temperature range of 10-27'C

http://www.screwfix.com/app/sfd/cat/pro.jsp?cId=102636&ts=83948&id=70871
£10
Danfoss Ras-C² TRV 15mm with liquid sensor, temperature range of 10-27'C

http://www.toolstation.com/messages.html?code=48000&mainWin=1
£8.26
Liquid sensor with frost protection. Can be fitted horizontally or vertically. EN215 approved. Working pressure : 10 Bar. Temp range : 8°C to 32°C.

http://www.toolstation.com/messages.html?code=80954&mainWin=1
£4.50

Or even this one for £8 which comes with a 5 year guarantee?
http://www.plumbworld.co.uk/0-753

Is it a case of where I would be paying more for the name rather than the quality or are the more expensive ones really much better?

The branded ones seem very popular and fetch a fair price. Are they worth the expense?

 

[gas4you]

Generally yes. I always fit the Siemens trade TRV unless I have to match existing ones.

 

[simond]

We use the Honeywell V200 or Drayton TRV4.

The Honeywell uses a standard lockshield/TRV valve so the heads are interchangeable, very useful. You can fit manual ones and upgrade or move TRV heads later.

Particularly handy where we specify an RF room stat. If the customer takes it into a different room they can move the manual valve head with them.

 

[pototea]

Thanks all for the very helpful advice.

I had a good look at the Drayton and this one from Toolstation (which was half the price at £8.62):

http://www.toolstation.com/index.html?code=48000

What swayed me in the end was that the one from Toolstation came with a 5 year guarantee & the Drayton ones came with a 1 year guarantee.