In a town that is already struggling to compete with itself and of course Southern California where the Vietnamese food is unbeatable, it's very difficult for a new pho restaurant to stand out on its own hence why you have places like Pho Saigon 8 who have the formula down right and are currently on their 3rd location which is doing extremely well.
I've lived in Vegas for 5 years now and I know where all the good (and bad - DO NOT go to Pho 87) Pho restaurants are. That being said, I've also only lived in this area of town. The two pho places that stand out are Pho Saigon 8 and Pho Little Saigon...and of course you have Pho MaiLan and Lemongrass Cafe which are "ok". Pho Saigon does well because of its name and because of its location (close to the freeway and LVAC. Pho Little Saigon has the unfortunate problem of being in a location that is slightly difficult to navigate through but I equally enjoy that location as I do Pho Saigon 8.
Pho King is in a better location and has two routes of access which makes it easier (and less of a hassle) to go to than Pho Saigon 8 AND it is in close proximity to EOS Fitness. With that being said, i only tried the pho there and I can say that it unfortunately wasn't my favorite...also, when I'm in a Vietnamese restaurant, I would prefer to hear Vietnamese music and I believe they were just playing a top 40 hits radio station.
I would say that I would give it another try but with so many other options close by, I don't see myself going back anytime soon :(