I used to play this a lot a ways back (we had one at work). I've had my own for a year now. I finally got my lazy butt around to cleaning and tuning it tonight (probably the first time ever since it had low plays). Wow what a difference, quite a bit faster now.
This is definitely one of my favourite games and will never leave the collection. It's not the fast thrill-ride of some other games (ACDC, ST), but the theme is so well put together and the rules are so ridiculously deep. This is one game where I don't try to look up the rules and figure it all out. There's so much to do that I want to discover it just by playing it and enjoying the new discoveries (I just hit my first pretzel multiball since owning it, had no idea how I got it until I looked it up). I don't even really use it to practice being a better pinball player. I just like to chill out and enjoy it. I even make a point of not playing it too much so I don't get too familiar with it, just play about one game a day and enjoy.
In regards to dead spaces and drains: I guess there are some dead spaces in that there are just rubbers around the right ramp and stuff instead of the narrow standups you find in newer sterns. If you have your shots dialed in you don't hit them often though. As for drain monster, I don't find this at all. It by far has the longest ball times of any game I play (20 to 60 minute games on average), and I have my outlane posts on second hardest setting. The only thing I find a little hard is the left outlane - it has no rubber post, and it sneakily slants to the left. So if you catch a ball and it goes all the way up the inlane it almost always drains into the outlane. I keep telling myself to watch for that next time and try nudging it somehow but I never remember. How long you last probably depends on your strategy. For most of my life I've always just tried to get through the TV modes to get to Alien Invasion (sometimes twice in a game). In that case the shots are Krusty, get to the upper playfield via garage or treehouse, then your play is in your upper playfield and you are safe while the ball is there. Get couch multi-ball then you can hit a pile of other stuff on purpose or incidentally (otto 2x, itchy and scratch, left loop, etc.,) without fear of ending your ball. Lately I have been trying to figure out the rules on my own and maximize/start otto 2x, daredevil, etc., instead of just going to the upper playfield, and I did find my games to be a lot shorter/suckier. So I say just go for upper playfield/multiball and let everything else fall into place if you want long games. If you do find TSPP really hard I would wonder if you have ever played something like ACDC pro - it's just mean and nasty, a 15 minute game would be a really good game.