I do not use clip tuners at all because of some reasons:
• In my opinion it's an aesthetical sacriclege to leave a clip tuner at the headstock of any type of guitar while performing. I also wouldn't put up a clown's nose while playing in front of an audience
• A few weeks ago, I listened to a guitar ensemble. Two of them (both Frankhähnel guitars and - I guess - brandnew carbon strings) put up a clip tuner, telling some droll stories about the next piece or lame jokes about guitar tuning while tuning before playing every single piece. The guitars detuned extremely quickly while played, I could hear that. Of course, the clip tuners were removed before playing. That procedure took one or two minutes each time. I usually don't need more than 10 to 20 seconds to check & tune 6 strings by the devices mentioned below. Do clip tuners need a longer time to get the frequency?
• I boycott devices with coin cells inside, because you simply don't find that kind of batteries in German supermarkets
On stage and band reherasal, I play via piezo pickup into a L.R.Baggs Venue D.I.-pedal. There's a tuner inside which mutes the output, so I automatically don't annoy the audience while tuning. At home, I use a Korg CA-1, because it's faster than the good old tuning fork.