I'd imagine an upside to this pen over the GVG is that if you wanted to go out into nature or hiking or something of the like, it's not only something of an issue to lug around the GVG (most likely in its case to protect it from breaking) but also if you had someone walk up on you which is always possible outdoors outside the privacy of one's own home, a pen would be easily concealable, and its way more discreet than using a torch and a long suspicious looking glass pipe, being lit in what to many appears to be a meth-style smoking appearance.
In terms of accessing hyperspace reliably and optimally, the GVG is the way to go, but there can be some upsides to this pen I think. For some, the GVG technique can also be hard to get down, and there can be quite the learning curve, so for those who truly struggle, perhaps the pen could be a nice alternative.
"Science without religion is lame. Religion without science is blind" - Albert Einstein
"The Mighty One appears, the horizon shines. Atum appears on the smell of his censing, the Sunshine- god has risen in the sky, the Mansion of the pyramidion is in joy and all its inmates are assembled, a voice calls out within the shrine, shouting reverberates around the Netherworld." - Egyptian Book of the Dead
"Man fears time, but time fears the Pyramids" - 9th century Arab proverb