But only when in the drops, in my experience.
Why would you not be in the drops on a fast descent in the wet?
The problem with road riding for me is keeping it fresh. Repeating the same routes over and over on the club runs week after week gets old fast. So much so that I elected to stay at home on Saturday and then shamed myself into going out solo after the missus went out leaving me. Don’t seem to have the same problem on the MTB.
OP, if it’s only a 6 mile commute then I’d do up the Carrera. Maybe even convert to single speed if possible to keep maintenance low. Get slicks to make the commute faster. Could probably use your MTB kit for the commute and investigate the shower facilities at work first.
As for flats, I used mine with a pair of Wellgos the bike came with for the first two years before swapping to Eggbeaters first and SPD-SLs later. Wished I’d done it sooner afterwards even with all the gentle fall-overs, and the saddle to coccyx interfaces using SPD-SLs without realising they were one sided entry only!