ᐅ Front door, which manufacturer?

Hi, we are currently looking for the right company for our front door as part of our house construction.
It will be an aluminum door with a side panel.
We have now received several offers, and the prices are quite similar.
All have the same features and are RC2 rated.
The prices range from 6418 to 6870 euros.

So now the question is, which door manufacturer will be better for us in the long term?

Offer 1: 6870 euros for a Köster aluminum door.
Offer 2: 6604 euros for a Kompotherm door.
Offer 3: 6415 euros, also Kompotherm.
Offer 4: 6749 euros for an Adoro (Schüco???) door.
Offer 5: still waiting for an offer for a Hönig door.

All prices already include possible discounts.
There are some differences I don’t understand but noticed in the offers:
Offers 2 and 3 include an “automatic door threshold.” What is that?

Offer 1 has a construction depth of 88mm (3.5 inches).
Offer 2 has a panel thickness of 99mm (3.9 inches).
Are there major differences here?

I hope you can help me.
Thank you very much.
Regards

We received a quote for an aluminum front door with a sidelight for just under 4,500€ including a motorized lock. Currently, Groke is offering the "All Inclusive Promotion 2017" with a U-value of 0.8 W/m²K, RC2, with overlapping panels on both sides.

That would be nearly 2,000€ difference compared to your offer. However, I can’t really make a comparison myself; others would need to weigh in on that.

Perhaps there might still be regional price differences? Is your quote inclusive of delivery and installation?

Yes, our offer includes installation. If you look at the PDF from "Groke All-Inclusive 2017," the base prices are already listed there. That roughly corresponds with my offer. It also depends on the size of the door and side panel, etc.

Does anyone have experience with the company "German Windows"?

Inotherm door with fingerprint scanner and motorized lock, laminated safety glass (VSG), and side panel with triple glazing. All together in DB703 color for EUR 5350. Installed for 4 months now and satisfied.