Not on the NX-5200, but I've used them on NX-210's and TK-5210's.
The KRA-25 works marginally better than the stock antenna. It's got a tiny bit more gain, but not a huge amount. Trade off is that it's a tiny bit narrower in bandwidth if you are using for amateur use. Our officers used those on their NX-210's for years, and other than the annoyance of the longer length, they were durable and gave us a slight edge over stock. Only had one shorter female officer that kept her KRA-26.
I've used the KRA-28, and it seems to perform the same as the KRA-26. Obviously more bandwidth, which is great if you are using the radio for ham use. But it's a stiff antenna and only the top half is ~sort~of~ flexible. Not something I'd want to carry on my belt.
I think I've been using the KRA-26 most of the time. Just not a huge performance difference.