At the end of the day ive never had a problem with a coach transfer, they are there to be used, you pay for them, youre keeping the coach drivers in a job, what would happen if everyone started listen to that advice! No-one would be getting on the coaches for fear of being dumped somewhere!!
My advice to everyone is, when you arrive, find your rep if you have one, ask which coach is yours, tell them to give you directions to it in the coach park, go and find it, when located ask the driver if that coach is going to your destination, show him your luggage ticket, although most understand English, if you are told yes then there shouldnt be any problem at all.
If you dont have a rep then you just double check with the driver that its going to your destination, if people get on the coach without really double checking that its the right one then its their fault if they are on the wrong one really isnt it.
Each to their own mode of transport really but thats just my view on it all.