I have the Downtown soft pannier. Considered the boxier Office as well. The selling point for the Downtown was i) shape – looks more like a briefcase and ii) strap – you have to remove the shoulder strap for the Office, but the Downtown can fold the strap inside without removal.
The Downtown is not as waterproof, but this has not been a problem. It is about 4L smaller and not as square of corner. Spare clothing is just about OK, but after laptop, case, accessories and some wotk, there isn’t a lot of space left. I’m currently using my Deuter rucksack on a road bike as I race after work on some evenings.
Either pannier will be well made, waterproof and robust. Get the QL3 fitting and the mounting stays on the rack, which is great if you only use one bike to commute.