Perhaps I've been unlucky with Gouramies.
In the past year I have had ten dwarves (six red and four blues) in my 250 litre tank. I am now down to the last one!
I purchased them from two different LFS, so cannot be sure which came from where, but the first red one passed away in just two days.
I know they are very nervous and susceptible to bullying when new to the tank. Also, I read rumours of flawed (diseased?) batches at wholesale breeders, so expected some losses, but not on this scale.
Much as I love the Gouramies, I'm going to avoid keeping them in future. Unless someone can recommend a hardier variety?