Actually, it's the other way around.
The reason that the X does a better job of equalizing flow is because the crossover paths are far 'gentler' in the X and offer less restriction to the crossing flows.
I've tested both, there is no "Crossing Flow" on an H-Pipe. It's a straight connection pipe to either side that allows flow to balance as needed. The X-Pipe's converge point leads to back pressure that doesn't allow the exhaust to balance freely, thus imbalance is more of a possibility. The X-Pipe's converge point "Forces" the flows to meet, the H-Pipe's connector "Allows" it, so saying the X-Pipe is 'gentler' isn't true all all. It's why H-Pipes are great for those that run on the track & generally spend most of the time at higher speeds, balanced/quicker/easier exhaust flow. However X-Pipes have that back pressure which is ideal for low end applications, such as from a stop. Amercainmuscle has their description backwards, they claim H-Pipes are better suited for low end.