I guess I'll chime in here since I run it. Lemme start off by saying this is my 2nd car with MS. My first was this abomination:
http://www.cardomain.com/ride/2180426
And my current car:
http://www.jzxproject.com/bbs/garage...vehicle&CID=14
SETUP:
With that out of the way, in regard to the 1jz I think setting up the ignition is the hardest part. I had a friend of mine who had already done it help me out with that part. The problem is the 24 tooth wheel on the crank has no missing teeth so you HAVE to use the 2nd trigger. Which requires another conditioning circuit. After that you have to make 6 outputs for the coilpacks. Once that's set up it's smooth sailing.
TUNING:
The hardest part of tuning it would have to a) setting up the parameters/base map and b) the cold start. There are a few formulas to figure out your req_fuel numbers and basic equations to get it started and idling. After that its a lot of tedious fine tuning. Nowadays mine starts perfectly as long as it's over 60f outside. Any colder and I have to give it gas and keep it on for the first minute or so. But this isn't the MS's fault it's my own laziness and lack of motivation to tune the cold start. I'm prefectly content to warm it up a little with my foot for the next few months
My only real complaint is the lack of resolution (12x12) but that fix is coming soon. And honestly the carruns great for my purposes. I really wanna try the stinger out but that's a ways down the road. I'm not saying the MS is bad or anything. I just like playing with EFI
I think I'll be pulling my motor in a few weeks here for some major upgrades. Maybe I'll unwrap the harness and take pics or whatever. I also have an unmodified MS at the shop so I can figure out what the hell my friend put in there for ignition!
Bigaaron makes an excellent point. This is not for the EFI noob. Even if you have a drop in unit you have to kind of know what you're doing. I don;t think I would have one if I didn;t have my own dyno haha.
I would never give a customer of mine an MS unless he knew what he's getting into. Your average "have someone else tune it/bolt on mods/I care about smooth idle" type of person wouldn't be too happy.
In short, It's a great system for those of us who drive/tune/track our own shit. Not so much for the fickle, daily driving public. I'm not saying you can't make it run perfect. You can but it's a lot of tuning.
My $.02