i own and use matco determinator, snap on solus pro, launch diagun, auto enginuity, and vag com. plus i own a few bootlegs like volvo fcr for 96-99 volvo.
with that said, i use vag com the most since vw/audi is my main work. the launch has been more than good on bmw/mercedes. it will not do air suspension on x5's, but autels will. When i run into one of those, i borrow a friends autel. yet it will code other modules i run into so far on bmw. stuff like light control modules. buy used light module for 100 bucks, program it to car and bill labor. still a **** ton cheaper than oem and you make good money on the job and customer saves. so yeah--it opens up doors that you had not opened
the launch has surprised me w/ what it can do though. i help local machine shop out and they are domestic guys mostly. i have had no issues doing obd1 gm and hooking up to ford/chrysler via launch. however, launch will not get into dodge ram-- so used solus/matco for that. another thing i liked is the wireless. i had a car on the rack, walked into the main machine shop a good 20 yards away filled w/ 3 phase equipment running and never lost connection to the car idling on the rack.
launch also got into volvo--esp 96-99 stuff that i had no or limited access to. It is pretty damn good on jag, i like it more than the auto enginuity/snap on capabilities there.
for the money, it is worth it. it is no autologic, but it is nowhere near the price of auto logic either.
i have used it on some asian stuff too. infinity/nissan/honda/toyota so far since i owned it. had no problems there.
now what i see w/ the ebay launch stuff-- those are chinese imports. the deal with launch is you get a user name and pw to go online, download files and update. so as long as you have a username/pw, you are good to go. as the website will never know if you have a valid or bootleg copy. as you dl files to a sd card and hook it into the launch. with that said, you can get away w/ a 600 asian knock off provided that if that seller/person ever flakes on you--you need to be buddies w/ someone with a valid launch to get updates from their account. furthermore, if you have a problem with your scan tool--good luck on getting it fixed. because if it is a knock off--where would you send it to?
as for the speed issue--i find it no slower than say otc/solus to setup the car. it is deff faster than autoenginuity. once i have it chosen, it loads data just as quick as anything else. if there is a scan tool i want to toss across the garage it is the snap on solus. that thing pisses me off and is what forced me to buy the launch to begin with- as i needed a solid scan tool for bmw use. it has fit that bill and then some.
do a search on youtube. there is a ny mechanic group who did a shoot out of scan tools for bmw use. i used their info as well as my hands on use when i was searching for my next buy--which was the launch.
I used it Saturday, grabbed it off the shelf, turned it on, and then walked out to the car in the parking lot. It hadn't even finished booting by the time I walked out there. But when you need it, it's nice to have. Like when the 80 year old owner next door walked over asking if we had a funky 3-pin caliper press adapter for a Tiguan. 
