After having done a raft of CE flights over the last few weeks, I have come to a conclusion - OLCI is pointless and actually works against you.

Let's be frank, the SSCI machines at T5 are a dream to use. I have never, ever had to queue to use one and you can get a boarding pass in about 30 seconds. You are forced to walk past them on the way to security from the lifts so you are not even walking out of your way.

It is, overall, a substantially faster experience then logging into ba.com and doing the check-in process, followed by a stroll across your office to the nearest printer. And, of course, you then have an extra piece of paper to look after and remember to take home.

Now, seating. I prefer 2D. However, if there is someone else in 2F then I would rather take 3D, 4D etc .... whatever row is required to avoid a seatmate. No seatmate means no-one crawling over to me to the loo, no risk of having his drinks or food tipped over my lap and extra space to spread my personal stuff.

Using OLCI, there is no way to guarantee no seat mate. Even if 2F is free, there is still plenty of time for someone else to be put there. However, when you check in at the airport, you have a choice. You can stick with 2D (pre-assigned when booked) or, if someone is in 2F, move to an empty D seat. Yes, there is a chance that someone might still go next to you, but it is a fairly small chance, because most people now seem to OLCI and PYOBP.

I don't see the downside. I have my preferred seat anyway but I retain the chance to change it by using an airport machine. The airport machine is quicker. There is no risk of losing an upgrade as there is nowhere to be upgraded to! You could argue you may be better treated if the flight is cancelled at short notice by not checking in, but I doubt it. At BUD last week, I was able to move to an earlier flight on a non-flex ticket, and not having checked-in already probably helped, not hindered.