double glazing - anyone used this company?

[audiobookman]

Sorry if this is in the wrong section please feel free to move it,
Ive just been getting some silly quotes of a number of double glazing companys for my whole house, this includes 2 doors and cut in / fit french windows as well as 10 fairly large windows.
Zenith windows took the mick with nearly 20k first quote then was dropped in half - by this point it sent him packing.
Ive had some other good quotes from 7.5k to 11k then i had a company quote me £5400 all in.
http://www.discountwindowwarehouse.co.uk/discount-window-warehouse.asp
It seems very cheap, they are listed on the fensa website and have bricks and mortor shop.
Has anyone used them before and what are your feelings - to me the windows look and feel good quality so im ready to hire them.
thanks for any feedback.

 

[nara]

In my experience, a small local company will do a better job, at a better price, than any of the big boys.

...despite all the "You buy one, you get one free" or the "60% of all windows" crap.

 

[audiobookman]

yeah i had first glass windows quote stupid money as well, they said get the front done and get the back done free, so effectivly i was just paying for the front - nice at 11k.
Im sure half of these place just pick a number out of the air and try to get you to take out thier credit. Infact im sure that most of these companies are just that, credit services and posing as a double glasing firm on the front.