Unfortunately i have very bad experience with those. First i bought Balanced and at half of the first gig low B and E started to sound dull and almost without any sustain. I had few backup EB slinky sets because i was at the start of the summer tour last year and putted them immediately after the gig on my main bass, and they lasted till the end of the summer, 15-20 gigs without any problem.
I sent MarkBass email next morning with the explanation and proof of bad sounded strings, and they reaction was surprisingly polite, they sent me 5 new sets all of them was different labels (Balanced, Energy, LongEvo, Groove, Ultimate) but with my favourite gauge and it took only few days until they arrived because they sent them me with DHL. Anyway, one year after i tried all of them i can say that 2 out of 5 worked well, and it was Groove and Energy. Other ones had that same problem i had with first set except Ultimate where only low B was gone dead same day i installed it.
Just to mention that i play bass since 1992. and i'm pretty familiar with restringing and basic guitar setup, every time i put new strings i use crimp and cut method. And most important thing is as i mentioned before, i tried other brands like EB, DR, RS, DA and every single one of them is working flawlessly. Of course that they also lost crisp and clear sound after some time, depending on numbers of gigs and rehearsals i have. I play Fender jazz, Fernandes APB and Esh basses, and never had any similar problem with any other brand besides Mark Strings.
That's too bad, because i really like the sound and feel that i got from those two sets (groove and energy) that worked for me. I might give them another chance someday, especially because they were way beyond nice for sending me all their string models to check after first fail, but for now i'll stick to more reliable manufacturer.