Sound — 10
Well obviously this doesn't give any kind of sound effect to your guitar but what it does do is give you true bypass - when you click the footswitch in your sound is muted and wherever it is placed in your effects chain, the sound wont be affected in any way. This is perfect for some sneaky tuning inbetween songs at gigs and also means that you don't have to worry about it affecting your tone - the Boss version does not have this luxury.
Overall Impression — 10
It's hard to get excited about a tuning pedal, but this one really is worth going out of your way to look into. When you compare it to handheld tuners in particular, you will instantly 'feel' the difference - none of that random fluttering that plagues the handheld varitites. The way the lights 'swell' so accurately are it's main feature for me - it gives you an accurate reading for how slightly sharp/flat you are by using a swelling technique that is hard to describe here. The lights are also extremely strong - they will show up perfectly outdoors on a bright day and obviously in a dark gig environment. I'd be gutted if I lost this pedal and would instantly buy another one. I'm trying really hard to find a negative point about this pedal - nothings perfect and I hate giving straight 10/10 reviews - but this really doesn't have any noticeable downsides. It is what it is - a tuner pedal, but this just happens to be a very accurate and easy to use one which is certianly refreshing considering the huge amount of other uselss tuning pedals/handsets that are on the market.
Reliability & Durability — 9
To be honest I'm not familiar with Korg pedals so I'm not sure if they are known for their Reliability & Durability or lack of. This pedal seems tough enough though so I wouldn't need to take a back up to a gig. It's also got a nice sloped design on the face of the pedal so your foot will connect with the pedal more naturally, eliminating an awkward stomp that might damage the pedal.
Ease of Use — 9
Ok, this is 'just' a tuner pedal so it's certainly easy to use, however it's this ease of use that makes it so much different to the huge amount of other tuner pedals out there. I've tried the Boss TU-2 in the past and was not impressed with it - to me it performed exactly the same as a handheld tuner and with a 60 pricetag I couldnt justify it. The Korg however is (slightly) cheaper and much easier/satisfying to use, I just had to get one. The manual is simple and straightforward going into the right amount of detail about the pedals 4 different tuning functions. The functions are basically just 4 different display modes which lets you 'personalise' how you tune up - it's a nice touch but I'm not convinced many people will use anything but the first mode.