For such a long article there's not much mention of the various effects each offers or doesn't, I/O, or how they SOUND. Just a lot of words, imo.
It does sum up the intuitive usability of each well though. The Line6 is more understandable, the BOSS more confusing. At least to the novice user, and at first glance.
I personally owned both the M9 and GT-10B and the only thing I found that the M9 did better were drive effects. And being small.
The BOSS won out for everything else. Better sounding modulation, for starters, usable envelope effects (M9 has no touch wah at all, or any bass wahs even), and on and on and on. And the M9 has no expression available, and a much more complicated way of accessing banks/presets though the M13 is better than the M9 in that regard via it's dedicated scene button.
GT-10B wins for me. There's enough usable drive effects, and enough excellent sounding amp sims that you can literally use the unit without an actual amp if you wanted.
One correction to the article: I believe the M9/M13 does in fact have a "Whammy" effect via a pitch effect. But you need an additional expression pedal to actually use it, where the GT-10B has the expression as part of the unit.

