The cable companies do not rent TiVos. They rent their own generic DVRs. Everyone I know who has one, and has experienced TiVo previously or subsequently, hates it. They do not work nearly as well. They’re buggy. The interface is bad. They do not offer the features that TiVo does (online scheduling, multi-room viewing, downloads from Amazon & NetFlix, dual-tuner capability, wishlist recording, suggestions, pad live events, etc)
Last time I checked, TiVo has a money-back offer for a 30 day trial. Give it a shot. If you really think the cable company’s DVR is better than the TiVo, or that the TiVo isn’t worth the additional cost, give it back.