Lantus vs Levimir

Lantus vs. Levimir Question.
Malachai is on 17units and is burning through vials. I've heard that a lot of people with Acro's prefer Levimir. Why is this? I know that some cats experience a sting with high doses of Lantus but if that isn't happening (yet), should I still switch?
I happen to have a hookup where I can get Lantus vials pretty cheap. Mark's Pharmacy would cost me almost $200 every 5 weeks so I'm not sure I can afford that.
Thoughts on this?
ALSO, IF I were to TRY Levimir and not see any changes/improvements, could i switch back over to Lantus or will that mess up his system/depot?
I'm not very educated on Levimir and how different it is from Lantus.
Thanks!

 

Here is a old thread, but a good one about the switching to Levemir:
http://www.felinediabetes.com/FDMB/threads/attention-lantus-to-levemir-users.122941/

 

This is great! Thank you.