Who do you think would win, based off the stats and abilities? (for the sake of attempting to avoid confusion, Transformers may or may not be included in the Marvel Universe, depends on preference). The choice is yours...
Most interestingly, though, it has everyone so far who has given a definitive winner, picking the Marvel Universe.
This is a bit of a surprise to me, even if the people are joking, but they don't seem like they are, because my earliest discussions on comics, way back in the 1980s, ALWAYS had people telling me that DC characters were overpowered compared to Marvel characters, without exception.
I believed that without much doubt until I started participating in online forums and seeing that there were quite a few characters at Marvel that WOULDN'T fold to the likes of the JLA, that DC sported a number of Daredevil to Spider-Man and Spider-Man to Thing (Fantastic Four) level characters, too, and that it apparently has pantheons of what most consider gods or reality-warping characters as well.
There may not be nearly the lack of power at Marvel that comic fans used to tell me; it might be a bit closer than people think.
Avengers vs JLA? JLA on average.
Young Avengers vs Teen Titans? Titans
West Coast Avengers vs JLE? JLE.
Great Lakes Avengers vs JLI? JLI (well, technically they're also JLE)
I used to wonder myself how long the Transformers series of the 1980s would have lasted if they ever decided to introduce Magneto as a guest character. Wouldn't want to be on the opposing side when THAT happened ...
But this overlooks the range of power actually possessed by the Transformers, namely the top-tier level of Unicron and Primus.
I looked at the Wikipedia entry for "Unicron" for instance, the planet-devouring figure they introduced for the 1986 movie and found the following as one of the entries for his comic-book incarnation:
------------------------------------------------------------------------------------ The third time the story was told was also in the United States Marvel series, this time by Primus, when he gathered all his children together to prepare for Unicron's coming. It was with this telling that we learned that Unicron predated the current universe, and had destroyed the previous universe which existed before the current one. He had slept peacefully, alone in the void of un-creation that remained, until fragments of the old universe that he had overlooked reacted, causing the Big Bang and birthing the current universe. The "sentient core" of this new universe recognized the threat that Unicron posed, and so created Primus to counter his evil and be guardian of the new creation.
------------------------------------------------------------------------------------ http://en.wikipedia.org/wiki/Unicron
Two ways again.
Like the disparity between Odin being a helpless would-be victim of Rogue in a "What If...?" series where she maintained her hold just a moment too long on Thor in her 1981 debut, and the depictions of Odin as a true "god" of the Norse pantheon, capable of decimating most hero teams on his own, let alone his own son, Thor, whom he can apparently strip of all power at will.
There's a range of power and abilities depicted for single characters as well as this group as a whole.