For starters, in the comics Barry, traditionally, didn't time travel without technological help...the cosmic treadmill. This tachyon device could be a stand-in for that.
The "other Reverse Flash", that is, Wally's Zoom, wasn't so much a speedster as a time-traveler. He had so much control over his time-travel abilities, he could make it appear he was a speedster, and Wally needed some help from Jessie Quick in order to defeat him.
Wells may not be a speedster the way Barry is. He may have time-related abilities. My only question is why he can do the Flash-type vibro-voice.
Well, in time we'll find out.
he could be like Zoom, as wasn't Zoom not really one with super speed, but one that could be ahead of time?