Force 200 or Force 300-25

PTP link of two ePMP Force 200. Channel width 40 MHz.
Replaced with two Force 300-25, identically set.
No benefit from it other than money spent, bandwidth as with the old except some added occasional nebulae.
What justifies replacing Force 200 with Force 300-25 for PTP links?

I don’t have either any more (N or AC PTP links) but I know when we were first doing PTP with connectorized N radios all were 40Mhz TDD 75/25 and I’m pretty sure I remember most were hitting about 170Mbps down. When we swapped them out with AC (we were using RF Elements horns/reflectors so we literally just popped one radio off and and another on) I was getting around 250Mbs down in 40Mhz 75/25.

I understand that you are using 200 and 300-25 so not exactly the same but I can’t believe there’s not a significant difference unless there is something else going on with that link.