If your cat is bouncy and tends to dive, stay away from Lantus.
I have no idea why everyone, including vets, are for lantus for diabetes where there is a lack of consistency in blood sugar level. A change in Lantus dose takes 5 days to take effect. Really, a dynamic diabetes disease is a good fit for Lantus? You need something that is straight in and out in 12 hours for a cat that has these occasional drops and spikes.
I can tell you this much....most vets only know by the book diabetes which one curve is set for the cats life. They aren't experienced with cats that have a dynamic diabetes. If your cat bombs out, they will be like oh well, he bottomed out....not our fault....lets re-adjust the Lantus and take a curve in 5 days. In the meantime you lose a ton of money and horrible stressed emotions.
It's just really shameful, to be honest, for vets to be like this from a lack of experience from dynamic diabetes. Text books aren't enough. But, they will take your money and act like they know how to handle it.
On a side note, I was able to lesson the wide swings in my cat's sugar levels when I placed him on 100% wet DM canned food. I still get occasional drops, but it is much more easily managed. That means, he recovers more quickly from the dip with Prozinc and wet food. It also means he can get back on his normal dose after about a dose and half period.
I am currently using Prozinc. With the wet food, I get a pretty nice flat-ish curve most of the time.