A couple of things. First, I'll have to disagree with a previous post that said that Ghost Ring sights are no faster to acquire than BoMar / Novak. If your front ring is painted bright orange (as is the JP Enterprises ghost ring sight - I've only seen it on a Glock), they're probably the fastest, funnest sights I've ever shot. Now, as far as practicality, no way. They ARE easier to snag, but on the other hand many concealed holsters are being manufactured now with larger sightramps in order to accomodate larger sights such as the ghost rings.
Second, I'm with the previous poster about the Ashley sights. They make some great stuff, but it all depends on what you want to do with the gun. If it's concealed carry you're looking for, get the Ashleys - preferably Big Dot tritium pros - although pricey they're some of the nicest concealed sights I've seen. PT Night Sights are the only other reasonable tritium sights IMHO. If it's just a general plinking gun, possibly competition, BoMar or Novaks are fine, but then again it depends what kind of competition you're getting into. Argh! Short questions often bring long answers.