Eight ball can be found for a lot cheaper than EK and is pretty fun, EK is EK however...

Eight Ball and Eight Ball Deluxe are two different games

I've owned two Eight Balls but only played PAPA's EK, but it seemed that at least in competition EK was just shooting the spinner, recovering, and then shooting the spinner again for as long as possible. On EB you're just shooting the spinner from the right flipper, while from the left you've got the eight ball or the bank shot to go for, a bit more variety, and both sides can be valuable enough depending on the rest of the game state to make you consider passing the ball over to the other flipper to shoot for them.
For games where much of the gameplay involves going back up top, I prefer the nudging play of EB's four lanes, plus the arrows on the middle, and the possibility of going around the bank shot from the right lane to EK where there's basically just the center lane and two dead bumpers.
I also find EB harder to get control of than EK with its larger slingshots and no left inlane, which for games as simple as they are I consider a positive.

I'm sure someone with more EK experience can offer a more refined opinion on it...

I think how it works is that when you go in the top saucer, you get whichever letter is lit above it. Maybe there's another way too...

Whoops. Must have missed that

i do like both but im a little bias because i own an EK and it is awesome. so obviously my vote is on EK. as for your question on how to light super... when the ball drops in the top hole whatever letter is pointed at by the lit arrow will light. you can sometimes nudge and bump a bit when its about to go into the hole to get the letter that you want because the EK pop like things to either side of the hole change the lit arrow letter light. and there is the very dangerous red center target that will light whatever letter the arrow is pointing to when hit. the spinners also change the position of the arrow.

Eight Ball is good but EK is better

also something to note, in case you were unsure, when you light super you get an extra ball typically (depending on game settings). When you knock down all the drop targets it light the spinners, causing them to be 1000 per turn rather than 10 per turn. this is why people in comp. shoot for the spinners so often. but man does it feel great when you rip one through the spinner at high speeds for a 1000 per turn.

I own EB and it's a lot of fun and brutal to play. EV however has a great theme for its time and of course drop targets. Drop targets always win!