replacement windows

hi, my boyfriend is looking to replace the windows in his flat. he's had a number of quotes, some coming in at double the lowest.

does anyone have any knowledge of the quality of LochLeven & CR Smith as these are the two he seems to be considerring.

both say they have 10yr guarantees, including on the installation

thanks

HI,
lochleven windows/platinum services both the same company.

have been doing my fabrication/ supply work for 4yrs now, i have never had any problems with them, delivery, specifications have always been faultless.
the quality is every bit as good as cr smith and the prices 25% less.