It depends. I don't really have an issue with playing faster in games you are winning vs losing. I do that in formats I like better than others sometimes too.
Take Hornacek for example. his average speed in MD games is 5 hours. Yet in my seasonal ladder game his speed is 2 days 18 hours. Is he stalling to get better matchups? Well, our game has been pretty balanced (I am pulling ahead now), so I would say probably not. And if you look at his ladder history, he is playing slow in most of them...so he might just be extra careful on the ladder:
https://www.warlight.net/LadderTeam?LadderTeamID=10430But if you actually take extra turns when you have clearly lost (like the example in Purple Issusions post), that is BS I think. It is not actually cheating, but it is shady for sure. Sometimes I might take an extra turn to make sure, but I usually say so in chat to let my opponent know (and I have had many people do that to me as well).
Edited 8/19/2015 13:48:25