I think see what he's saying. Around town you're stopping and starting, going no faster 30-40 Mph, so the up right riding position is great. But on longer journeys on free-ways, motorways, (dual)carriageways, ect you'll be doing 60+, so naturally your riding position will change, you'll lean in more. and you won't be stopping and starting as much. So I guess he's found that uncomfortable.
Personally, the only annoyance I've had at 60+ are the mirrors; as soon as I lean in I can't see jack behind me and have to make exaggerated movements to check the lanes before moving.
Also, I am starting to wish the seat had a wee bit more padding.