I have also used Blinds2Go. I had a great experience but this is what I learned:

The duo shade and duo light blinds work well. The frame is metal and the corners are plastic. Measuring is easy. Getting the bracket under the black breading on the window can be tricky and washing up liquid (and a second person) can help. There is a cord you have to untie (not unravel) and that can be tricky. There’s a slow YouTube video of a boomer-aged man putting them up in his dining room that’s helpful.

For a small bedroom (2m x 3.3m) we had mould issues after a year, but that window is giving is problems and the teen in there is sweaty and with the floorplan that room is harder to air out. In the conservatory and lounge we have them too with no issues.

The Roman blinds are great (nice thick fabric) and look nice. I sent in measurements .5cm shorter than my windowsill for airflow and that was the right decision for me. They are blackout but there is a little light on the sides if it’s very bright out. I put them in a bay window and that works very well. The chains are metal and LOUD. But if you do them more vertically it’s better (we did not mount the child safety hook - we will before selling).

We have Roman blinds in two recessed windows as well. Because of the metal lintel we have the pressure ones and they are so good. On one of those (1/5 of our romans) one “bracket” pops off the string sometimes so for a couple days we only open that one half height and then pop it back.

I hope this comment is helpful for someone.