I've had the K70s on my G5 for about 1000 miles now and have started to push them a bit. They are everything I could've asked for in a tire. They are very neutral and precise steering. They stick very well. They handle well in the dirt. They don't push the front end like the Avons did. Frankly, I think the Avons that come on the G5 are garbage.
I don't notice the rain grooves, but my front tire pressure is a bit lower (24 psi ) than Single's.
They are my choice for a tire. they have given me confidence in the Bullet that I never had with the Avons. They may not last as long as some of the others, but my experience with some of the Cheng Shins and such would not cause me to buy them. They are too hard and and don't stick particularly well. Granted most of you guys don't appear to ride like I do, so it may not make a difference to you, but I prefer performance to long mileage. Ya know the old adage, How fast do you want to go? How much money do you have? Fortunately though, the K70's are a steal.
Bare