I priced out one of my frequent trips, from BKK to SGS. QR/Blacklane charges around USD $75 for a Mercedes E class, apparently including meet at the aircraft door. SGS charges USD $140 for the same service. So in that regard, it's a bargain.
But let's compare based on what I usually buy. I don't need to be met at the aircraft door. I just want the ride from the airport to hotel. SGS charges USD $72 for that. I didn't see an unbundling option with Blacklane to buy just the ride. So if you're looking for the meet/greet service, Blacklane might be a better choice.
But wait. Blacklane includes only one hour wait time. And you order the car for a specific time at the airport, not to meet a specific flight. What if your plane is delayed en route by, say, ATC? And what if your plane doesn't have Wifi so you can let Blacklane know? The hour runs out before you land and Blacklane leaves?
I'm going to guess that there are still some things to iron out.