Why and how is Tor an overkill? With Hotspot Shield, you are trusting them with everything you are doing. With Tor, there is no trust with a single server because it is decentralized.
Tor is certainly far more decentralized, but you seem to harbor a common misconception that Tor doesn't reuqire trust. The exit node of your circuit (the last hop before the "real" internet) handles your directly. At best, the destination of your packets is unencrypted, giving the exit node a narrow but pertinent view into your communications. At worst, the entire packet is unencrypted, and the exit node can manipulate it in whatever way it wishes, undetectably. This is why you must, must, must layer other encryption on top of Tor, ie, HTTPS. As they say at the Tor Project, "plaintext over Tor is still plaintext," except that you've attracted a lot attention to send it.