I agree that MAN T1 isn't ideal at the moment but there is the small matter of practically the whole terminal being redeveloped, so of course there's going to be hoardings and disruption. The new security area will open 3 weeks today so the majority of the landside works will disappear after that. Malaga airport is in a very similar situation with all the work going on there.
The worst airport I have flown through recently was Murcia. It is far too small for the amount of traffic it now handles. The queue for security was 25 minutes long despite there only being four departures, the terminal itself was cramped, there was virtually no airside seating available and only one (rather expensive) outlet to buy food and drink.