Quoted from Tuna_Delight:Sounds offhand ("seems sluggish") like you may not have the game playfield slope set steeply enough.
I'm going to give the opposite suggestion here: I think you likely have it set TOO steep. Gottlieb recommends their games be set with a 3.5 degree downward slope. That is usually achieved by setting all the leg levelers are the same level (the game is essentially set up at 3.5 degrees at the factory). In practice, I've found you need to raise the back legs just slightly - perhaps half an inch - to achieve a 3.5 degree slope. (I check mine with a digital level I bought off Amazon.)
The steep slope is likely the cause of constant outlane draining. Think about it: the steeper the slope, the greater the force of gravity, and the less likely the ball is to "jump the gap" and continue to the flipper. Mine is set at a 3.5 degree slope and I get about a 50-50 split on balls rolling to the flipper.
Many people, especially those who have grown up on the newer games which are set at much steeper angles, feel that EMs are "too slow." That's an argument for another time. But Gottlieb designed the games for more side-to-side action, and that East-West action is best achieved with the 3.5 degree slope.
I would also HIGHLY recommend that you wax your games regularly. It makes a HUGE difference. Some recommend waxing them every 100 games. I recently bought an Atlantis with a Wade Krause repro playfield. First time I played it I thought it was good. But cleaning and waxing it, and setting it at the proper slope, DOUBLED the speed of the ball. I now wax it every 100 plays and it is the fastest EM I've ever played. Is it as fast as any game from the last 30 years? Nope - not even close. But no EM is - as EMsinKC said.
Jacks Open is a GREAT game. It's a bit different than other classic Gottlieb wedgeheads in that it has two distinct sections - the top third with pops and rollovers and then the bottom 2/3rds with the drop targets. It is very difficult to get the ball back up to the rollovers, so you spend most of your shots trying to nail the drop targets, and because they are straight across the playfield they are very dangerous. Good luck hitting the red queen without it coming SDTM. But when you get the Royal Flush lit, and knock those five targets down a couple of times for specials, it's a great feeling.