when did your premie switch to regular formula?

My pedi says we can switch to nonpremie formula (Similac Sensitive), and the girls are certainly caught up on size, but I'm wondering what the point is of switching?
They've been on neosure this whole time, it works great. Why would I switch them to Sensitive? why wouldn't I just keep them on neosure?

TIA

My 33 weekers were never on preemie formula.

My 31 weeker switched to regular formula at around 10 months. My dr.s reasoning was because he was caught up to his peers weight wise. Continuing with the neosure would have continued the weight gain and being too heavy can be a bad thing.

Now at almost 2 years old he's at the 2 % for weight and drinks pediasure everyday. He's a tiny little thing now! I wish we would have kept him on the neosure for longer and supplemented with pediasure once he was on whole milk. He's still in 12 month pants and will be 2 in feb!

my 30 week baby got switched at 33 weeks so was only on pre term stuff for 3 weeks but it was only to top up my BM

My son's doctor put him straight on /Similac sensitive and Vit D. He had acid reflux so he was on zantic and the pediatrics said he didn't want to change him again at the same time my son was a late term preemie.

DD is 15 months/12 adjusted and still on neosure, partially because she hasn't been gaining well. But they will be switching her to a toddler formula soon.

my 31 week preemie was on it untill his due date which was when he was pretty much up to a normal birth weight.