There are some minor disadvantages to using a dynamic IP. If someone who previously had the IP address you've been assigned did something nefarious on a service you use, it's possible that IP address might be banned. Usually, VPN providers are very careful about checking their IP addresses against blacklists, so the chances of this being a problem for you are slim.
They even offer the most generous simultaneous connection count, with six simultaneous connections through their network, where everyone else offers five or fewer. NordVPN's network isn't as large as some of their competitors, so if you're trying to obfuscate your tracks, you might want a company with more servers. Otherwise, this company is clearly providing a winning offering.