My biggest wins have came from Live betting so for that reason I do prefer Live betting over pre-match. I do however bet more pre-match.
I prefer pre-match betting cause the odds is higher than live betting, and i will do some arbitrages if my pre-match betting will be lost, so i will have chance to keep my principal, which is the key of sports betting. if my pre-match bets go well during the match, i won't do arbitrages cause i can make profits as more as possible.
Unless you have a bot and a big bankroll arbitrage to any kind of value is next to impossible in my experience. You prefer pre match because of bigger odds? That isn't always true, when the game starts the odds can change massively in your favor over pre match if the other team or player gives a surprise or two.