Just my 2 cents on what these 2 game plays would affect the tournaments.
I play and have played at least 8 different games and still have decks to include but not limited to: pokemon, magic, VS, wildstorm plus others since 1992.

With the experience in 2/3(magic) and single play (pokemon/wildstorm) in a tournament environment. This is my opinion and would like to hear from you all.

2/3 play single lim or swiss needs sideboard. In this game play being able to tech in cards for round 2 or 3 allows the original deck to be more themed and solid, which would invite playing with non-main stream cards, in turn getting more cards in the tournament environment. Sideboard in 2/3 also breaks the cynario deck A beats deck B, but deck B beats deck C etc. which would allow rouge type decks easier to play with.

With single play (swiss play being a must), sideboards aren’t needed and tech cards are in a deck usually as just a single card. Making decks little less solid or themed but putting in an element of surprise/ or luck of the draw for that deck b that always beats deck A. But this environment decreases the rogue decks and people adhere to archetypes instead because you only have one chance to prove your deck can run with this combo. The hype of this game play is you get to play allot more players and takes allot less time. It’s appealing to the fast action play of the game and has the feeling you are going from one comic issue to the next to duel in a battle

The one thing I'd like to comment on first:

No Sideboards!!! It doesn't decrease the scenerio "Deck B beats Deck A but loses to Deck C," sideboards allow a dominant deck to ensure it will never lose to a rogue deck, because their sideboard will contain Flame Traps and Have a Blasts (or whatever else the metagame calls for).

Sideboards are acceptable in some games. Vs is not one of them. Even if they stick with best 2/3 in swiss style, at no time during a tournament should sideboarding be allowed. Not in Swiss, not in finals. Not now, Not ever.

Yes, no sideboards! A deck must stand on its own merits, not on the merits of how powerful the metagame cards available for the game are. Sideboards are a mechanic I actually strongly dislike, as it increases the luck factor in a game. Game 1 the decks must win by earning it, games 2 and 3 are won by the player who draws their metagame hosers first. No good.

I belive Drafts/Sealed should be 1 game formats but not Constructed, and yes I have played the one game matchs at the Pre-release and it was not that bad but really stresses you more.

decently constructed sideboards would have contingencies for those other sideboarded cards.

I believe in sideboards, but just not now, when the game is too young. Especially when the game strategy is still mainly:

"CRUSH! BASH! BREAKTHOUGH! PUMP! HURT YOU!"

When people start using more of the strategies that the game has to offer, like the X-men recovery, or the discard that the game provides, yet no one uses, People will start to need other factors to be able to counter this, where 60 cards of "Pure BASH" won't be able to cover all of this.

Just look at rigged elections. eventually people will have to find goo sides for these guys.

60 cards of pure bash!! Rigged Elections was just the thing to counter that. I have a couple decks myself that are designed to beat those that just bash an opponent.

Sideboards would cause the game to be nothing but smash 'n' grab. Simply because they could have 60 cards designed for mass damage, and when the deck runs across rigged elections, they can throw in their 4 have a blasts or flame traps or what have you. This doesn't hurt their smash 'n' grab deck, because Rigged has no way to deal damage anyhow, so they can afford to lose some pumps.

Sideboards promote nothing but quick damage decks, because tricky decks like R.E. are the ones that require sideboards against, and immediately lose to a sideboarded deck.