Agree with many comments on here, and disagree with many as well
USB to upgrade code has been a big innovation, but a blessing in disguise.
It means that bugs and code can be easily updated, however as a direct result of the fact it's so easy, code doesn't get polished as much before it's initial release.
If a code update meant that a set of ROMs needed to be burned, sent out via post to each machine and then swapped with the originals I can guarantee the code would be near complete on first release.
Just think of the number of older machines with obvious and detrimental bugs (Sopranos, FT & HS2 spring to mind immediately) which need a code update, but aren't readily available due to the hassle involved. Let alone the number of 'modified tournament ROMs' which have been written (DM & JY).
The current ease of updating allows for bugs to be found (by players) and fixed, but also allows half-ar$€d code to be released in the first place.
Use of magnets has been significantly more varied, and frequently used, than previously.
Other changes (for the better?) include the use of LEDs, carbon steel balls, titan/silicone rubbers, playfield protectors, plastic protectors, leg protectors, improved audits, the list geos on. There have been lots of small changes which have drastically improved the 'play experience'.
I also have no interest in playing against someone over WiFi. First of all - I just don't see the point. No two machines can ever be set up identically anyway. What would it achieve? Much preferable to play head to head against someone.
I also don't see the need/point in having 'toys' for the sake of it. Yes it was cool the first time I saw Things' hand come out and take the ball on TAF, or the T-Rex swallow the ball, but after a couple of times it gets irritating and hold up game play.
The depth and subtlety of rules has been the greatest leap forward, surely due to the computing power available in modern boards. IMdn can tell if a shot was made by the autoplunger or a flipper, which way the ball arrived at the spinner, etc. No more cheap Revs on HS2 because you used the autosave to replunge the ball, no more extra ball awarded in LotR, MM or
AFm because a ball in MB arrived in the scoop from the pops. Modern games tend to hold the interest of players for longer due to the difficulty in achieving the Wizard Mode, which benefits both machines on location, as players will pay for another go to see the next mode, or homeowners who won't get bored with a machine and want to move it on after a week.
There's no need for Stern (or any other manufacturer) to try changing, or introduce radical new concepts, which not only will cost significant money, may not even be received positively. JJP added Bluetooth compatibility on DI which is always disabled for any comp, and usually off on site as well. On their PotC they had the rocking boat and the 3 spinning wheels, neither of which were great and have been either modified or removed for the latest release.
Change for changes sake is not needed.