You have to appreciate, that as a seasoned videogame collecting veteran, telling someone to get a MAME cab or a supergun, sounds to me like me telling a pinball collector that they don't need to bother with these unreliable pinball machines when you can play pinball on your PC in pinmame these days
My preference has always been to have the whole "experience" i.e. standing in front of an arcade cab that actually looks like it lived in an arcade back in 1985 and thus I would only go for original machines. I do however understand that some people like to buy these new multgame cabs that people make and sell on ebay as they look modern and clean, just be careful if you go that route as quality and price vary greatly and it can be a minefield getting the right one
My preferred advice remains, get an appropriate condition working Jamma cab as a starting point. This then gives you 3 options :-
1) If you want the 100% accurate gameplay experience then you can buy genuine Jamma PCB games to put in it
2) If you are happy with a 60-in-1 type multigame, then you can buy one of those, but as
@ShootAgainChris correctly states the multigame PCB's do indeed have glitches and sound issues. If you hardly ever play videogames you may not notice or see it as a problem, but a collector that is familiar with the game can always tell that they are not quite right
3) If you wanted to go the MAME route (I.e. PC running MAME with 6000 games on it) then its easier than ever before. If you have a Jamma cab, there are plug and play solutions these days that allow you to plug in a MAME PC to a Jamma cab using a JPAC (Jamma to PC convert board effectively + appropriate video card or drivers) so you still have the option of swapping in real arcade pcbs or multigame boards as and when you fancy it.
