Same here. I have the MLBTV package and will always listen to the Giants announcers over just about anyone not named Vin Scully. On MLBTV you can do the audio overlay with radio too. Jon Miller is the Giants PBP man on radio and is excellent too. I think I will listen to him this week.
Like others said if Marty sticks to just PBP he is still very good. But he comes off as a jerk,grumpy old man when starts giving his opinion on just abut anything. That's when I turn him off. He didn't used to be that way at all. I think all of those losing seasons along with losing Nuxhall as a side kick made him bitter for whatever reason.
As for players trying to lift a fly ball for a sac fly, I do think some try to do it. I can remember years ago Pete Rose saying he would try to upper cut his swing when he was in sac fly situation. But I do think more than anything it depends on the pitch and where its located if they are able to get enough lift and distance for a SF.