A friend of mine just got a 04 999 and also bought the slip on termie with ece and air filters.
The dealer was giving me a bunch of talk saying it was going to be hard to put on, and you have to be careful putting the ECU cause it doesn't have the right might, and what not. I figured they just wanted to charge my friend $300.00 bucks to put it on.
I told him I'll put it on since I've done it on my 748 and others 998. Man, it was the easiest thing to put on. Everything was plug and play and it sounds awsome.
The hardest part was changing the ECU cause you have to take the battery set up apart since the ECU is under the battery. All in all, it took about a little less than 2 hrs to complete the job. The dealer was telling me it would take about 3-6 hrs to complete it.
Oh, I call Ducati and they said since he specified the exhaust to be slip on for a 04 999, the map should be the correct one and should have a problem.
Anyway, I just wanted to say it was easy to put it on. A lot easier than putting a full system on a freaking CBR1000RR or slip on.