Join Date: Feb 2006
Posts: 24,647
Is he a really loose raiser post flop? In that case, you might like to sit on his right, because he will self isolate. If you're in a multiway hand with him, you can bet, he'll raise you, and this will chase out some of the other people.
Aside from that, and even if he is a loose raiser, you should prefer to be on his left. He's only in position to straddle once per round, and having position on his in all but one hand/round is to your advantage. Playing UTG to his straddle, I would tend to limp way more often than I'd raise coming in. I might limp my whole range unless I had a very good hand and could guarantee a favorable SPR on the flop.