Windows - struggling to find information!

[HouseIsOnFire]

Hello, really struggling to pick between two companies and wondering if anyone can help! I'm being told things by both sides, but I don't know if it's with merit or not! Have only managed to get 2 quotes - have rung and rung various local companies (not the terrible national ones) and they just don't ring back...

It's for 5 windows, all 2m high, acoustic laminated glass

Company A
8 week lead time
Avantis locks
Deceuninck windows
3,400 (down from 4,300 to "match" the other company)
10 year guarantee

Company B
4 week lead time
Yale locks
Brand not mentioned
3,100
10 year guarantee

Both sides selling their locks as the best locks and google no help!

I can't really work out if Deceuninck is the be all and end all!!

Thank you for anything windows-related you can tell me!

The frame manufacture and quality of fitting are the most important factors.

Thank you, am struggling to find out if Deceuninck is a good brand or not - I google and everywhere is "we fit Deceuninck, top manufacturer" but of course they're going to say it if that's what they're selling!

The two companies are both same score on checkatrade, trust pilot and both Fensa accredited.

Check on companies house how long the companies have been running. If they dissolve the company and start a new company then your ten year guarantee is worthless. Although a long running company can still dissolve it is less likely. Also check whether the directors of the company have been directors of similar companies. Will give you a better idea of whether they have a tendency to dissolve and start a new company when things go wrong.

Thank you, one has been around for 40 years, the other 25!

I think I'm just going to with the slightly more expensive one as the windows had 4 different lockable open positions whereas the others had 2... not much of a difference but still!

Ok, the other brand is Veka, if anyone knows anything about them please?