You last picture is a great example imho because I don't see why you wouldn't be able to reach that spot with a CXS and the angle attachment. And this is basically what I see all the time - so please correct me if I'm wrong. I think this is a very interesting topic!
Kind regards,
Oliver
What I like about the Bosch offset/eccentric chuck is that it accepts full ball-detent drill and driver bits. The other feature that I value is that all 4 attachments use the same interface and offer a range of connectivity options. I believe the CXS angle attachment accepts wire-detent and Centrotec bits, but I could be mistaken. I have found that Centrotec bits have a far more limited selection of availability in my area whereas there is an abundance of standard 1/4" hex drills and drivers that I can easily obtain.
Funny, I never considered the little Bosch bulky, as my only point of comparison is my T18, which makes the Bosch feel tiny in my hand. I know others love their CXS drills and speak most highly of them, no doubt good capable tools. I too would value a side by side comparisons of the Bosch FC and Festool CXS solutions to see how they compare in close quarter work in corners. Another significant factor in my decision was the large price/value difference and the fact that the Bosch 12V batteries fit so many different tools in their "system".