I bought the B1. The B2 just has a USB for computer connection. I preferred it because of its low cost (I found it for just under 400 euros) and the reputation of Korg. The pros are:

- Nice sound, standard piano. I would prefer it to be a bit brighter, to be honest, because I mostly play ballads. But if you put it on the second level of dynamics, it sounds louder. I always use that and add a bit of volume. It's good, I wouldn't call it perfect, but I like it and enjoy playing it.

- It has a button that instantly resets the default piano settings, in case you have made changes and want to quickly go back.

- It doesn't have many buttons to confuse you, it's easy to change sounds. It's a simple instrument that does its job right away, completely plug and play.

HOWEVER:
- Strange charger connection. It's not easy to find another one if the cable breaks. I came up with a solution by keeping the original charger, which I couldn't find with the same plug, and making a connection with the cable so that I only have to replace that if it breaks again.

- Strange pedal connection, with 4 small pins. Two of them have broken, but fortunately it still works.

- And the most important thing: after just 2 years of use, and only indoors, without dust, it developed a problem with the dynamics/aftertouch in 9 keys, where they sound very loud even when pressed softly. Even in keys that I never used, like the ones in the highest octave. I have had keyboards in worse conditions for many years and never had such a problem. They asked for around 200 euros to repair it. I refused, of course, and took it to a private technician who will replace the entire set of keys for around 100 euros. In fact, the technician at the store had another B2 keyboard for repair, with the exact same problem!

In conclusion: I do NOT recommend it. Problems with the charger, pedal, and keys, which are not few... And all this in a short period of time, within 2 years, just after the warranty ended. I realized that I need to increase my budget from around 400 to around 500 euros for something reliable and relatively cheap. Now, since I had a bad experience with Korg, I would probably go for the Roland FP10 or a Yamaha, which my friends have had for a longer time and haven't had such issues.