Greer offers the credibility of being a former major leaguer, Coolbaugh is someone who has worked with and had success with several of the Rangers' younger hitters.
I don't really have an opinion on this. I don't know who the best coach would be. I do think that, for the Rangers to contend in 2010, having Josh Hamilton and Chris Davis get back on track, and having Ian Kinsler hit more like he did in 2008 than in 2009, is pretty key.
I don't know what coach is going to have the best results with those guys, though.