If you are a walker, you surely don't wait to see what the umpire has given. You hit it, see the catch and immediately walk towards the changing room, just like when you're bowled. Maybe a glance back to see if you have been given, out of curiosity.
A few umpires in our league wait for a few seconds to allow the batsman to walk. It gave me a nervous moment when I got a clear stumping!
I don't agree with the paid umpires argument. They aren't perfect, so honest cricketers help them. If the ball goes for 6 and it is tight, fielders usually let them know. If a catch falls short the fielder lets them know. I'm surprised it isn't more common in international cricket with DRS and media attention. Gilchrist is one of my favourite cricketers because he was so honest. I do love Athers too though.
If I didn't walk in a tight situation to win a cup or league, it would spoil it for me. I don't want to win like that. It isn't that important.