I wouldn't exactly recommend a Blast for a first time buyer my self if asked, and im transparent about that, the heart wants what it wants though. The only big down fall to the blast is the original MS2930 and MS2931 monitor chassis's can be a temperamental if they encounter any major faults I personally never a had a ton of issues with blasts during testing time the limited few that did have issues with monitors its a real chore to work with but I manage to get it squared away somehow.
If you were to buy a blast city I would read up on the manual some and make sure you find a spare MS2930 or MS2931 chassis at some point just one if you can.
When you get your cab take 30 mins or an hour and just look at how everything is wired and familiarize yourself with where things are and how they get from point A to point B this is honestly something I would recommend for any new cab purchase anyway.
Outside of that the only thing really about blasts that may create further frustration is the sheer amount of extra wiring and interfacing boards and connectors. The blast city was designed to be highly modular because it was released during a pivotal transitional period in arcade hardware. It was made to run Jamma, Model3 and (Half) JVS by easily swapping some wire harness's around and or adding a IO board for JVS. This basically required sega to add additional looms and a interfacing board. So if and when you ever need to do serious troubleshooting and your not super familiar with all the guts nor want to put in the time to read up on a manual and follow that stuff then your gonna have a really frustrating time until you just sit down and mull through it all. That really shouldnt happen all too often though realistically. The monitors is the big turn off on these cabs, when they are running correctly they run very well though.
Everyone thats bought blasts from me have been really happy with them.
Im not really a blast hater but there's a lot more going on in those cabs compare to some others past or present but they are built well and when they are tuned up and running correctly they just run as expected