Only you can really answer that question. Most the difference will be where their data centers are and which ISP they connect to. This can affect your performance but this is also highly depended on where you live in relationship to the data centers, what ISP you are using, and likely most importantly what internet servers you are access via the vpn.
Pretty much this is one of those things you need to test yourself, luckly VPN providers are fairly inexpensive so you can sign up for a number for a month and see. You want to try mulitple data centers on each VPN they may have different ISP connected to them.
Other non technical things like how good their billing is etc I don't know