Barring injury, Mike James is going to get about 20-28 minutes a game and has a track record. Not being the focus of the offense I would say he'd be good for 7pts. 1 3pt 3 assists and .3 stls. He does turn the ball over more than I like to see and has limited upside in any other area. but he is usually consistent and can explode on occasion.
Acie has a lot of potential but like most rookies he will struggle with his fg pct. have high turnovers and struggle to provide assists. Even if he is the starter, he still has a steep learning curve to overcome and IMHO might be a good second half pick-up.
Before I'd settle for James I would scour the waiver wire again. There are usually several better players available. If you set your lineups daily you could even drop/pickup guys who are playing each night rather than settling for 2 or 3 games a week of Mike James.
FWIW I wound up dropping James a while ago and replaced him with Juan Calderon.