Their DVR is nothing more than a glorified VCR. No name-based recording, no favorite actors, etc. If you've never had a Tivo, it'll be a step up. If you've had Tivo, it's like going back to 8-tracks.
Picture quality wise, there's no difference between the two services. You'll find people that will argure there are, but you'd need 65 inches to see it. DirecTV has the edge in sports, otherwise the progamming's even.