Hi @maf,
Ubuntu 16.04? Please upgrade!
I have achieved the best results using Turboprint – but I presume that much depends on what printer you use. It seemed as if Gutenprint did not like my Epson XP-960 (or vice versa).
The print result is extremely sensitive to what printer profile you pick. Every new kind of paper calls for a printer profile of its own – and the best profiles are those that you make yourself. If you will find a ColorMunki Photo at a good price, it will assist you with colour management from monitor to paper.
More info here:
Have fun!
Claes in Lund, Sweden