I myself Had the possibility few years ago to buy a 5726 at the AD and didn't do it. I did buy a Grönefeld, though, so my Overall choice would definitly be the Remontoire.
The question of swapping both now is much more difficult. If you do like the 5726 a lot, you could regret it for a long time. Even if you get one back after some time, it will probably not be yours. And it might even be more expensive. The value development of the Remontoire on the other hand is unclear. And even if you really like the Remontoire, the experience could be a bad one, because you'll always think about the gone 5726.
So, in your Position, I'd probably only Swap the 5726, If I'd plan to let it go anyway. Think of it that way: would you now sell the 5726 without the possibility to buy a Remontoire?