The Phantom-1 is an overpriced scam that you shouldn't support.
Although these sentiments are strong, they succinctly - albiet harsly - sum up my feelings on the Phantom-1 converter. My experiences with said device (the blue, supposedly better second revision) weren't all that positive, as I shall describe in the following paragraphs.
For starters, my first P1 produced garbled visuals when used in conjunction with scaling-intensive titles like SS4. Usually, this converter problem is attributed to loose, old, or "damaged" home system cartridge slots. However, since I was using the new converter with a "mint condition," modded system purchased directly from Arcade Solutions, said seller wasn't able to attribute the scaling glitch to my system and agreed to replace it with a second converter. Luckily, the second converter didn't suffer from visual glitching, but the fact that this problem has been reported by others, combined with the fact that it's not uncommon, does not bode well for so pricey a peripheral.
Secondly and perhaps most annoyingly, the converter requires an EXCESSIVE amount of force in order to attach and remove MVS carts from its female end. After a mere three cart attachements/removals, my P1's end connector started to crack, flaking off bits of plastic. Trust me, you'll get really tired, really fast, of forcibly "fighting" cartridges both off and on of the P1, should you choose to get one. Although some people claim the connector "loosens up" over time, mine never did. It remained annoingly difficult to work with up until I decided to sell it off via eBay and make it someone else's problem...
The final nail in the product's proverbial coffin it its cost. I don't know if it's still in production or not, (I don't think it is) but for as expensive as it'll likely be, should you be able to source one, you would be better off saving up for either a cabinet or, as another poster stated, a "consolized" MVS setup. In short, if you want to play MVS games, go with a "real" MVS setup. Unfortunately, there are no shortcuts.