Ease of server selection: A VPN connection tunnels through the local access point to a specific VPN server: With personal VPNs, you pick the server nearest to your access point. This will, of course, vary if you travel. Each personal VPN provider has different servers. At the very least, you'll want easy access to a pick list of servers.
Pricing: It's not simply a question of what costs less. It's a question of paying for what you'll use. WiTopia provides buffet-style pricing: access to all its servers worldwide for an annual prix fixe. At the other end of the spectrum, HotSpotVPN provides day rates and weekly rates, while Strong VPN bundles servers into packages based on location.
Performance: Using a fourth netbook as a control, I timed connection and load times at various times for common sites, including Facebook, YouTube, and several news sites and e-mail providers. Several loads included long videos to test buffering time. To eliminate latency, I set up a dedicated 802.11n access point and ran identical tests serially on each netbook.
As expected, the control was more responsive in stopwatch testing than the machines using VPN services, but except for video buffering, not noticeably so. Server load responses are notoriously hard to evaluate in this kind of test, but StrongVPN's servers seemed to show the least latency when buffering and streaming videos.
Of the three providers in this roundup, HotSpotVPN provides the most options and requires the most knowledge up front. It's great that the service lets you pick conference packages for a day or three days or a week, but you do need to do your homework before you buy.
The HotSpotVPN Web site is sparse on pre-sales information, and the support site is a no-frills affair with a knowledge base, trouble ticket system and FAQ. Unlike StrongVPN and WiTopia, HotSpotVPN does not provide online chat consultation for those who don't know whether they want to connect to a 128-bit Blowfish server via PPTP or something a bit more robust using SSL-based OpenVPN. But once you've settled on what you want, the site does provide some handy configuration videos to step you through the setup process for various operating systems.
The ordering process is quick and painless. Within a minute of ordering a basic one-month OpenVPN package (I opted for the least expensive and least robust 128-bit Blowfish encryption), the company had delivered setup instructions via e-mail.