Ubisoft have made it clear to thank the players for the closed beta for the game. Players got to test out the game during the beta. Ubisoft also said that they got to test out their servers. But many players had complaints of how bad the online was during the beta
One of their online architects called Lorenzo Aurea had this to say about the closed beta:
"every issue you experience during the beta is potentially one less issue you’ll see at launch."
If you want one persons impression you can see how it turned out when StoneFoxMedia tried it out:
One of the comments also pointed this out on their blog:
_"I genuinely enjoyed playing Rainbow Six: Siege....when I could play it that is.
I know it was just a beta, but if the launch has even 1/10th of the problems with matchmaking that the beta had, you're going to lose not just me but I'd wager a majority of the fanbase.
The fact that I had to spend 10-15 minutes in match making for every 2 or 3 minutes of gameplay is simply unforgivable. You absolutely MUST fix that before you fix anything else.
Aside from that, pistols need a nerf in general and you really need to re-balance the defensive and offensive operators.
Can't wait to hear what the patch-notes are going to be. "_
Ubisoft need to improve on the beta if it is going to play smooth during the launch. The game has no singleplayer content. The game is going to be released on December 1st 2015.