Sorry, just seeing this now.
Maybe you wanted to compare the Romeo3 and the Romeo4?
The Romeo1 is still only available on the RX.
I have a 1, 3, and 4. The 3 is super bright and I will have to look and see how that compares to max brightness on the 4. When you compare the 1 and the 3, the 1 is daylight bright but max is maybe 7/10 for max brightness on the 3.
I don't think you would have any issues with the 3 or the 4. I have run both on my MPX and prefer the 3 since it leaves you with more visibility around the optic and the seemingly larger lens.