I think the new service queue is great thing, it assigns very fast, you have can multiple security groups assigned to a service queue and a security group can be assigned to multiple service queue's.
For a lot of our customers I spoke with it makes perfect sense. You assign a ticket to a queue, then if needed a member of the queue can take ownership.
Yes, the send email action can be improved as mentioned, but don't let that stop you.
One other thing is that now if you go to edit incident, you can change assignment, ownership, pirority, name, description etc, all in ONE screen.
I don't think that there will be a huge learning curve, however keep in mind that you will have to Configure more in 7.5 to start. But it also gives you more freedom.