I am not a fan of pick-up only trains nowadays. Sadly, in these aggressive open data computer app days, many have scant respect for staff, rules or penalties and the ONLY way you can stop abuse of 'pick-up' only stops and avoid conflict is not to stop! This should apply to those long distance services that, in this case, are expected to be full upon departure from Paddington without Reading only customers. Not such a problem with inbound services as seats will already have been occupied upon arrival at Reading.
Trains with capacity should stop at Reading non-restricted, with westbound customers using space vacated by alighting commuters.
Non-stopping Reading gives a worthwhile commercial advantage to a small number of key trains in the down direction. In other words, bear in mind those high fare customers seeking a fast journey to, say, Exeter, who understandably would prefer not to be in competition with relatively short distance commuters for seats or otherwise.
Whilst I understand the comment about disadvantaging westbound customers from Reading, the flow is nothing like it is from Paddington. Using this argument perhaps all trains should also stop at Ealing Bdy, Slough and Maidenhead!!??

My golden rule on long distance journeys is to arrive at Paddington before most of the commuters to ensure no problem getting a seat, reserved or otherwise!! Numbers of commuters arrive last minute as they cut it fine, have many trains to choose from and take the first fast whenever that is! Thus introducing a fast shuttle with pick-up only services will not resolve the problem. The first fast train is the first fast train so far as commuters are concerned, irrespective of any nominal restrictions that may or may not apply, or where it may or may not be going after Reading!!

These are personal views of course, in the full appreciation that capacity is as ever finite, like it or not! The allocation of that capacity amongst the various traveller markets always has been and always will be subject of healthy tension!
