No, it only costs 1/2 your move in 5e rather than a full move, but Grease is an absolutely devastating spell at endgame against (a) plodders (b with bad Dex saves and (c) multiattack melee that they rely upon for their bulk of their threat. Plop it down at a chokepoint or in an open area to kite against Dex-deficient + melee dependent personnel, save your Concentration, and do other stuff.
My least fond memory of the spell was running an encounter where the PCs were getting some McGuffin in a Far Realm alien ship’s cargo bay (I was running the dungeon script for this railroad of a game that I intermittently GMed for this kid’s dad who would often flake on them).
It was level 18 (3 PCs) vs a wave encounter of ATST-like walker tanks w/ pilot + infantry personnel inside (get in room and deploy infantry while pilots man the tanks). First wave was low HP (basically mooks) drone flyers to soften them up. There were still some stray drones left up on round 3 when the ATSTs came. They were reskinned Fire Giants exactly as above; (basically tanks) meh Move + bad Dex Save + melee multi attack 10 reach + a plinky single attack ray (like a Boulder) + a 5, 6 Recharge big gun.
The Wizard had Grease down on the bay door they were streaming through straightaway and the next round had a Grease in the room for the team to move from cover to cover to kite and kill any ATSTs that made it out of the kill-box.
This was supposed to be a mega deadly encounter according to the CR budget the guy had put out there. The clustereff that actually ensued was titanic. It was a Benny Hill theme of action denial of melee multiattack and kiting around the cargo bay. Once the ATST’s spent their 5/6 recharge big gun, they were typically routed with their damage output per round decimated compared to what would be ideally realized.
Once out of the Grease, spending Dash to try to run around the Grease in the Bay to get to a PC or falling back on the crappy at-will ranged is utterly punitive. Eventually I just had both the infantry AND pilots leave the ATST’s to try to engage because while squishy fodder, at least they had the move + higher Dex save and there were more of them so I figured Bounded Accuracy would somewhat save the encounter (it didn’t save it, but the Benny Hill theme was at least turned off).
This has to be something people have experienced at endgame against things like the various Giants, a horde of Ogres/Undead, Golems in ancient tombs, etc. any Brute-like plodder w/ poor Dex save where action denial of their melee multiattack (primary threat) nerfs them significantly. It’s particularly devastating against choke points and in areas where you can kite. Dex is the worst physical Save in the game for monsters (only attack Int or Wis instead). Dinos, Treants, Zombies, Dire Animals. There are tons of low dex, reliance upon melee creatures that are easily kites or can have their action economy wrecked by Grease.
I looked into alternatives after this fight. Even if the GM would have reskinned a Stone Golem rather than Giant it would have been even worse because Advanatage on Saves doesn’t make up for the awful (even worse) Dex save + no actual ranged ability at all. Strategically placed Grease against this kind of enemy personnel + a Team PC that can even marginally kite (I’m not talking kitted out for kiting…just capable) is devastating to an up tiered CR encounter at endgame.
After my feedback to the guy, he tailored all future Mothership-as-Dungeon encounters around the Grease spell (no more ATSTs/Brute enemy personnel). I don’t love that as a solve, but whatever.