Yep - bought one for my son about a year ago. Impressions mixed and as a result sits around largely unused.
Pro's:
- Stick your smartphone on a tripod and get all your shots recorded. No deadtime in between a continuously running video. Nicely catalogued in terms of each shot i.e. have a look at the one that has the highest bat speed (or the slowest) and see the shot you played.
- I think everything in the vertical plane is good: Backlift angle, angle at impact, follow through angle, max speed, speed at impact etc. All seems reasonably accurate in terms of watching video and results. All this helps with bat speed, timing etc.
Con's:
- Fiddly to calibrate. Can take many attempts!
- Don't think anything in the horizontal plane is even slightly accurate i.e. categorization of on/off-side is rubbish. Have seen 80% categorized as on-side yet most shots were on off-side in the video.
- Cannot deal (or even correctly identify) cross-bat shots e.g. cuts, pulls, sweeps etc. And if it categorizes a shot incorrectly as this then you don't get the benefit of the vertical bat shot analysis that seems quite good.
- No recording mode (their main competitor smartcricket/batsense) has this e.g. start it, walk out into the middle, play an innings and download your stats. (This was on roadmap as coming soon a year ago)