I do, do it about once a month in Bristol (Southmead Hospital). They’ve started taking triple doses from me recently so now takes about 1hr 45 mins in total, but you can give single or double doses which take less time.
Has far less effect on you than whole blood donation. I think you lose about 40ml of whole blood. I always ride there and back with no ill effects (other than once having to wait 5 minutes to calm down once as i’d come in with a high pulse rate which would have adversely affected the machines apparently).
Think I’m now up to about 20 donations in the last two years and generally do it once a month although you can do it every two weeks I think.
Have had some nasty bruising on the venipuncture site in the past, but that’s because I’m not very good at keeping my arm still for that long… Have also had the lip tingling thing where there’s too much anticoagulant in the mix, but it’s easily sorted and again not a problem.