I'd say the Borg.
They're familiar with time travel. they are also better prepared for the disorienting effects given the fact they have a collective intelligence.
Well, in the Star Trek: Enterprise series....Archer is transported into the future...the 30th century, I believe...and the Federation and the Sphere Builders are involved in a war at that time..which the Federation wins. If I'm not mistaken, the sphere builders are from another dimension. And yes..I imagine they do have transporter technology.
Borg can also time travel, so that's basically a wash.
The Borg also have the ability to open portals to other dimensions (eg the war they started with Species 8472), they could attack the Builders in their own realm, possibly.
The Borg could most likely assimilate the Sphere Builder's tech into their own.
Robtard you make an excellent point and I don't think the Xindi or any species (other than 8472) have an immunity to nanoprobes. If nanoprobes were entered into a sphere or a sphere builder, then the Borg would learn that technology and how to counteract it. Plus getting past Borg defenses is very difficult - especially their shields.
__________________ "Great men are forged in fire. It is the privilege of lesser men to light the flame . . . whatever the cost"
Because of the Transmission the borg sent as seen on Startrek Enterprise would the borg of the 24 century retrieve it, enter the temporal cold war,
annihilate the sphere builders, assimilate the xindi weapon and xindi inside it steal it and use it to assimilate 22nd century earth? if so that would be one awesome season of star trek enterprise, with crew of the uss enteprise NCC 1701 E to help of course thanks to daniels telling picard and crew having it set in between Star Trek Insurrection and Nemesis