I have flown with Baby as a passenger from both Manchester and East Midlands quite regularly. On each occasion I have found the staff to be very pleasant and never had any problem with them.
As afar as the uniform is concerned yes it's plain, but whats the problem, if your paying £20 for a flight why you bothered what the staff wears.
As for the cost of a cup of tea, same on them all, I paid £1 to fly Jet2 to Belfast and £1.50 for tea on the flight, its something you have to accept, you may get the flight cheap but they got to make some money somewhere, if you are that bothered take your own drink with you.
Lets accept you arent going to get the same standards from a Lo-Co as you are a full fare airline.