As someone now selling his Vibergs because he picked the wrong size, maybe I'm not the best qualified to talk, but let me offer what I can based on my experience.
I would go TTS on what you wear in Alden Trubalance.
I sized down 0.5 on my Alden Trubalance to a 9.5 because I planned on wearing thin dress socks with them (Indy boots).
Whilst this works, the left Alden boot definitely feels tight and my toes are right at the limit.
I somehow assumed this would work fine for the 2030 service boot, but should have went with my "true" Indy size, a 10.
Wearing 9.5 in my Viberg 2030, the left boot is just not long enough. Also I do wear thicker socks with this boot, which contributes, but it really isn't the kind of boot you can wear dress socks with!
So anyway to summarise: go with your TTS/COMFY FIT Alden Trubalance size, or whatever you can find that is comparable to that.
edit: And if anyone can offer me advice sizing the Viberg 110 last, I'm all ears.