It's not scuba diver's watch but it's as waterproof I need (out in the rain, swimming etc).
Large display so I don't need my reading glasses!
Back-light so I can check the time in the dark.
Useful set of alarms, stopwatch, countdown timer and full date display.
With the number of functions available the instruction book is necessary but once read, it's all pretty obvious.
And the "Plus a bit" - it has compass and temperature sensor. Temperature is only accurate if you leave the watch off for 30 mins, otherwise the reading is bound to be influenced by body heat/clothing. Compass calibration is best regarded as a game, I don't think it's possible to complete succesfully! You have to rotate the watch tracking movements of the pointer at one second intervals, it's just not possible!
Once calibrated the claimed compass accuracy is plus or minus about 5 degrees, so if you're in the wilderness you'll still need a proper compass but otherwise: good enough.
As far as I can see the very expensive watches with a compass feature don't claim to be any more accurate than this so if you want a compass watch, no point in spending more, this will do, you'll have to accept that for real navigation you need a proper compass. Apart from that - it's a gadget freak's gimmick. (Guilty as charged!)
Overall it's comfortable, looks good, affordable, provides the functions I need well and, as a Casio, I'm sure I can look forward to at least 10 years reliable operation.
Did hit one problem - how on earth do you calibrate the compass? Carefully followed the instructions a few times, no good. It's like playing a video game but the computer is so much better than you that you have no chance of completeing all the steps in the limited time available. Lucky then, that the compass feature was not a key feature for me. So basically the "plus a bit" compass and temperature sensor are a fail. Nevertheless I'm still very pleased with the purchase many months later.