Garen's new Q jump does not put him in range for his spin.
Maybe others have noticed this but I have yet to see it called out on the boards. When you Q at max range with the new Garen, he jumps forward just a little bit to close the gap between you and the target. However if you immediately spin after the Q animation has finished, it will appear that you are in range to deal spin damage to the target but in fact you are just a hair outside of it.
This isn't huge my any means but I've noticed it mostly when attacking gromp or dragon as I will Q-E onto it and then check the map and such to plan my next move, only to discover that my E was barely out of range and no damage has been dealt.
Please give Garen the very slightest of buffs to make sure that his Q puts him inside the max spin range.
Thanks!