Obviously you are going to get a ton of varying opinions about this and it really boils down to preference. For example, I disagree with Puddsy... I think 55g Topre is the best kind of Topre.
That said, I agree with what a_ak57 said. I agree that the 55g plate RF feel vs the 55g PCB HHKB feel is very different and that the RF metal plate has a big effect.
I love my RF 87U 55g. Once I bought my HHKB Pro 2 and liked it, I thought about dome swapping. I tried a friend's 55g HHKB and thought it was ok. It was not as big of a difference that I thought it would be. I didn't dislike it, but I didn't have that amazing "endgame" feeling either. Anyway, things like the lack the arrow cluster eventually turned me away from my HHKB so looking to dome swap was no longer on the table.
As rowdy said, some people who have done the mod have reverted back. But the only way you are going to see if you like it is if you try it (someone else's or just try the mod yourself). You can always put the domes back in your RF.