Cover Valet is a brand which offers a couple different models. The cover valet model is hydraulic assisted and mounts high on the cabinet. I have seen major issues with that specific cover lifter. The hydraulic arms can be too powerful and cause excessive pressure on the crease of the cover which will eventually cause it to tear. Cover Valet did change the pistons because of that problem but even the newer pistons I find to be to strong for a new cover. The Covemate 1 (sundance specific) is made by Leisure Concepts and is a very reliable lifter. It is very simple and not hydraulic assisted but it gets the job done. In my opinion I would go with the cover mate 1 by leisure concepts.
