It's hard to find fault with either version, in my view. If the solid state version was never created, the EM game would nonetheless still rank among the very best EM multiplayer titles, I suspect.

As much as I like the SS version, I prefer the sensibility of the EM version. The EM's backglass composition is more appealing to my eye, with its cluster design of score reels as opposed to the symmetrical design on the SS.
The larger-sized array of playing cards on the EM backglass adds dimension, which is arguably more interesting.

Likewise, the EM reels simply look better than the vacant black abyss of the SS counterpart when the game is turned off.

Last, the EM's backbox better displays the backglass with its artistic graphic on the lower horizontal. The absence of that graphic on the SS disjoints the head from the cabinet, diminishing the aesthetic value, in my opinion.

There are few titles in which I would want both the EM and SS versions. Joker Poker is one such title. Each version possesses distinct attributes.

I am likely in the minority opinion, here. I prefer the EM gameplay. The resetting drop targets and enhanced bonus features of the SS version, etc. are subordinate to the clickety clack of the EM, for me. In fact, I prefer seeing my rare accomplishment (all targets dropped and remain that way) as I shoot for the upper rollovers and the lonely stand-up target. For some, less is more.

Several years ago, in about 2010, project EM Joker Pokers, with average cosmetics and overall good bones, were fetching in the $3,200 - $3,500+ range. A restored example fetched $5K in about 2014, as I recall (Odin's game perhaps?).

Transitional multiplayer Gottlieb EMs and scarce EMs generally have been particularly hot lately.