Solar panel installation

[battybird]

Have had a quote for 4KW solar installation on our east/west roof 12 panels on west and four on east (chimney shading part of the roof). They have quoted £6495 inc of everything. We would arrange our own scaffold as the roof has not been checked for a couple of years and OH wants to ensure it is all good before bolting panels to it. Also going to clean gutters etc and anything else while scaffold up! The panels are mono PV (Sunlink) and the inverter is an Aurora 3.6 power-one. Has anyone got any advice about what else we should be asking? We have ascertained that the company use their own installers, dont subcontract, that the workmanship is covered for 10yrs and the panels for 12yrs (90% efficiency) and 25yrs (80% efficiency). There is an insurance policy which covers the company for 10yrs too, and the panels have an insurance for the 25yrs as well as manufacturers gaurantee. The company does not seem to have been around for more than 2yrs and this is a concern, but on the plus side they were not at all pushy, did not add anything to the price initially quoted, and have sent all the info by email as promised. They assure us that the work would be done by 1st July subject to the survey showing that the house is energy efficient enough, strong enough roof etc. They take a 25% deposit which is refundable if we dont go ahead for any reason (except for £60 for survey). The other concern is that the figures they quote regarding the cost benefit is lower than other companies I have talked to...but I would rather underestimate than overestimate!
Very tempted, comments??
edit; got the company from advert on Selfsufficientish site

[Arnold]

As far it seems impressive. Indeed, I haven't seen any company offering depreciated efficiency less than 10% and 20% after Ten and Twenty Five years respectively. But they are offering 10% efficiency depreciation after 12 yrs which means +2 yrs of longevity! It seems good. And all other required speculations are up to the mark. Personally I prefer to go with a comparatively new company (if everything seems Okay) because they always try to serve their best to establish their Brand Value. So, go ahead.

[Green Aura]

Sorry BB I must have missed this before -hope it's not too late.

I can't advise on how good your offer is but don't take their advertising on Ish as any sort of endorsement. We have to pay the running costs like everyone else so have to allow advertising, I'm afraid.

Hi Arnold, welcome to Ish You don't work for the aforementioned company do you?

[Arnold]

Hey Maggie,
Thanks. No, I'm not from the Company.... I just expressed what I think, nothing else. After all, it's her decision.
For me, I always got better service from a Newly launched company which seems impressive to me.

Arnold

[battybird]

Actually, I did not even say which company and see there are several adverts..(at least on my page). I have held off for the moment as we are not sure that we want the panels on that particular roof although it means we can get 4kw...its much more visible. We have a smaller roof at the rear which is south facing and the same company have quoted for 6panels there but it will be £5495. The labour etc is more than the cost of the panels, I suppose. Cannot decide whether it is still economically sensible. Had wondered about the type of panel / inverter they offer, as our only experience is small ones from maplins!