I can share direct experience and professional opinion regarding this title since I work for an operator that owns one from the first run and remains on route in a very large barcade venue, Zombie version. I don't need to speculate with first hand observations. He paid a distributor price well under $6K. The games have sold well for the first two runs with a present backlog of construction, after that I have not tracked information.
Enthusiasts need to reconsider the market of who this game was targeted, and it was not PinSiders, or even pinball collectors new or old. It was an attempt to revitalize an area of interest which formally ended the last time in 1992. People forget there was THREE runs of SlugFest!, not two. The game sold well the first two times, and petered out the third due to market saturation. It seem to be working again with Gizmo Games, as many new players have NEVER SEEN a pitch and bat baseball game.
General reliability and durability of the game is average due to the amount of wear and tear that both the pitching motor assembly and bat receive. The pitching motor has already been replaced once due to burnout, as it received substantial play on location and earnings which have been very good. Power settings are adjustable for the bat which is quite important. Playfield durability has had no major issues. In regards to features it is MUCH LESS than Slugfest!, although it does have the curve ball feature, but no DMD graphics or home run mechanical ramp. Sound quality is very good with crowds and scoring. The only real bonus is the running man unit, which is not significantly different from games made in the 50s, 60s, or 70s, but is simpler to maintain with less working parts. Scoring displays are old school retro and not particularly robust, but they remind me of the old Milton Bradley handheld games from the 1980s.
If you are collector, IMHO, there are better options based on potential for long term support of the manufacturer as who really know if they will even be around in 2019?
The EM classics are much more robust in terms of overall construction.
Deluxe Official Baseball, 1962 World Series, Pinch Hitter, or 4 Bagger Deluxe (in at least in complete condition that have not been cannibalized). These are the "Big Four" of ALL EM baseball games. Most in superb condition (which is rare anyway) will cost an average owner between $2-5K. If you want "repaints" and "chrome" add at least another $1000, if that floats your boat. The primary perk of SlugFest! is the graphics and sound, everything else had already been integrated into previous games.
Gizmo Games title feels very disposable designed for the basis of operator use, as compared to WMS P&B games I own or have owned. However, this game on location, has already paid for itself in terms of cost, and continues to make profit with no signs of stopping. It remains very popular.