It's worth going deep more than broad, in my view, and taking an intentionally instrumental interest in the tool; fountain pens have never been a hobby for me, but rather a means in support of my practices as a notetaker and diarist, to the tune of 25 A5 volumes and about 4100 pages' worth since early 2018. These days it takes me four or five pages at once to notice any tiring or discomfort, and no pen that insists on itself even slightly could hold up to that kind of expectation. (Indeed I judge the Decimo more favorably than the 51 precisely because the latter pen tries my endurance much more, especially when I post its overweight and unbalancing cap.) Think of it like photography or high-end audio; here too we see the same sharply unfavorable knee in the middle of the price/performance curve, past which returns rapidly diminish and one mostly ceases to impress the savvy with anything beyond one's readiness to spend. (D850, not M10 Monochrom; HD6XX, not HD 800 S.)
I mean, I wouldn't turn my nose up at a $1000 handmade Pilot Urushi but I surely also would not buy one, not at least unless I meant to try to make flirting with ambassadors more than a once-in-a-lifetime thing. It's a beautiful pen and I'm sure it functions superlatively! Just that it belongs in far finer and less hardly used hands than mine. Good grief, I sometimes feel I make even my Decimo look like a sewing needle, and that isn't really at all a small pen, being by mechanical necessity about as long as its thicker, heavier sibling. But it also by far is the tool best fit to my hand of all the ones I've ever tried, and that's what counts, right?
(One final note worth making: the Decimo and Vanishing Point bodies are designed around the same nib unit, which I believe originated with the initial "Capless" models in the sixties. If you order a Decimo with the next nib size up from what you have in your Vanishing Point, then, the nibs and bodies will be fully cross-compatible!)