There are definitely many kitties who have gone OTJ on PZI, and I recall someone recently who switched over from Lantus, but I don't recall who.
IMO, much of the success with Lantus is because there is a clear protocol to follow, and a lot of support with others using it. With PZI, although we have some basic approaches that seem reasonably successful, there is quite a bit of variation in how people use it, and no clearcut document that I know of that tells people what to do. So I think we have more of a "take stabs in the dark" approach, which leads to much tearing out of the hair. :lol: PZI is an awesome insulin in my view, but it can be difficult to know how to use it effectively.
When you need a flexible insulin (shooting on non-12/12 schedule, varying the dose, etc.) my understanding is that those things are difficult with Lantus, so there are some specific cases where PZI is more appropriate. For cats/beans w/o specific needs for flexibility, I think either insulin is probably just fine. Perhaps the biggest thing I've seen with PZI is that sometimes people need to shoot more often than 12/12 for a stretch to get good results, and if that doesn't work for your schedule it's definitely a minus.
If you are thinking of switching yourself I wouldn't - you are getting good results on PZI, and will potentially lose ground during a transition. I would only consider switching if you have tried PZI for a while and just can't get good results on it, or have determined your duration is too short and want to try something that might last longer. I don't see either of those in your case though, but certainly there are kitties who fall in those categories and then I think switching is a good idea.