I also don't think the taste is that unbearable, but it's really bad for your teeth. It really burns the (only know the dutch word: glazuur) of your teeth away. It's best that after you come home to brush your teeth.
But the good thing about leaving the mdma in your mouth so it can absorb much faster into the blood and it also doesn't has to pass the liver, so it starts much faster.
But why do you say it doesn't last as long? Do you have some explenation for that? I actually don't have that feeling. Maybe it's because you drop multiple pills in an eavening, but you will only drop it when you start thinking about it and then wanting to actually take it but if you then just swallow it, it'll take another 45min. or so before it kicks in. Instead of when you let it absorb in your mouth it kicks in very fast (sometimes less than 5minutes!), but in that case it's true that your x-night/day 'll be shorter.