PCTel is an HSP ("host signal processing") modem. The short version is that it's a glorified telephone wire adapter for your computer, your PC does pretty much all the rest. This is no longer as bad as it used to be (they hit the market back when Pentium 150/16 megs was a "powerhouse" and you could actually see the mouse stutter and skip across the desktop when you connected), but the device still uses up cpu cycles and memory that's better used elsewhere. 9.99 isn't terrible, but there are better modems (LTwin, HCF, etc) for the same or not much more.
At a guess, it's more difficult to connect to a local provider because whatever you are using to connect to them (DUN or their proprietary software) doesn't have million character init string that AOL throws at it to force it to 1. connect under all but no signal circumstances 2. report 57600+ speed regardless of actual speed. In other words, you may want to look up the current strings to slow the "modem" down to 33.6 (or lower) speeds to see if it connects more reliably to the local ISP.