Because of the large amount of mass the overall armor contained (the shoulder armor alone weighed 12.2 kg), Vader did not often run, but was still capable of doing so if necessary. In addition, he was still capable of using Force speed, but rarely did so.
Darth Vader's loss of limbs prevents him from using force lightning, a common ability among Sith, making him weaker in comparison. Vader's reliance on his mechanical suit weakens him in battle, reducing his agility and mobility from his days as Anakin Skywalker.
At a further cost to his humanity, Vader is physically stronger in the suit than he was before his grievous injuries, and these enhancements likely extend to his speed as well. As Star Wars canon continues to explore the extent of Darth Vader's abilities, his blinding speed is the latest deadly ability to be showcased.
Imaginably his suit otherwise impairs normal running, hence his iconic power-walk we usually see. Too bad they were not aware of Vader's speed when they choreographed his battle with Obi Wan in ANH.
Darth Vader's love and skill for droids and mechanics, particularly from his childhood, becomes a major tactical weakness for him in Star Wars: Dark Droids #3. The Scourge targets Darth Vader and attempts to defeat him by assimilating his own droids, but their plan is foiled by outside interference.
In one comic, Vader once tore a metal door off its hinges. In another, he drive his fist through a steel table. There is a bit of a blurred line there, since the Force can assist with displays of strength, so that makes it harder to truly measure Vader's strength alone without use of the Force.
According to Lucas, Vader operated at twenty percent less strength than the Emperor. While this was still impressive, it also shows how much more powerful he could have been as Anakin. Had he emerged unscathed from his duel with Obi-Wan, conquering the galaxy would have happened much faster.
And it's true that Vader and speed and agility on his side, Thanos basically had everything else on his side. Thanos can also just manipulate time and trap Vader in place, He also could of snapped his fingers way earlier in the fight killing Vader in no time. It looks like Vader couldn't Force a victory.
Even after his brutal scorching in the fires of Mustafar, sand remained the only natural phenomenon that Vader feared. To him, sand was a reminder that he'd failed to save his mother or Padme from death.
Obi-Wan faced off against Darth Vader four times and physically beat him twice while beating him through his Force development in a third fight. Obi-Wan Kenobi had the high ground that led to Vader's disfigurement and becoming the ultimate Star Wars cyborg.
Up to Star Wars: Episode VI - Return of the Jedi, Palpatine treats Vader poorly, and they very much have an abusive relationship. Darth Vader hates Palpatine yet is eager to please him, whereas Palpatine goes back and forth between acting as a friend and showing his hatred.
He's not exactly slow, but his injuries and heavy armor made it a necessity that he not waste movement in combat. As such, what seems slow is actually calculated, precise movement.
And Vader could also simply use the force to rip off the gauntlet or simply cut off the Mad Titans hand, or even just hold him in place and strangle him.
As further highlighted by Vader and Kylo's redemption stories, it was a lesson that Kylo Ren never fully learned himself, which makes Darth Vader the more powerful user of the Force between the two of them in Star Wars.
The only way to truly combat the Force is for one to have access to it themselves, which Batman does not have. Thus, Darth Vader destroys Batman in this scenario, no questions.
Infil'a put up a fierce fight against Vader, almost killing him by throwing the already damaged Sith Lord off of a cliff. Despite severe damage to his suit, Vader survived the fall, and repaired himself with parts from Infil'a's droid, Arex.
Age and resignation. He's matured in many ways, become more patient and restrained. He learned from his defeat, and years of quiet study and contemplation. He's not always at the front anymore, and with no rules to restrict him, he really has no tension.
In Star Wars Legends and Canon, Galen Marek (Starkiller) is the only Jedi (other than Obi-Wan Kenobi) to put a beat down on Darth Vader/Anakin Skywalker. Galen was secretly trained as a Sith Lord apprentice to Vader, but returned to the light side and the Jedi.
8 Darth Vader's Armor Was Heavy Enough To Bring Him To His Knees. Darth Vader weighed 120kg (264 lbs), and most of that weight is because of the armor's steel and obsidian components.
I assume you mean purely physical strength and not skill and/or overall power. For the Sith (in canon), it would be Savage Oppress. Savage was a bred warrior and one hell of a brute. He received magically enhanced strength and speed from Mother Talzin, which helped him hold his own against some of the Galaxy's finest.
Overall, Suitless Darth Vader would be very powerful and would likely out-scale most Sith from legends and canon but with him not being balanced in the force and lacking mental clarity (which he would lack both of) then he'd still fall short of being the most powerful Sith lord.
