I have used a Hobbs for years and still do , but also have Two Grcs.
I wish I had some pics of a large medesto ash I worked on today to testify the Grcs. Theere was a 24" by 35 40 ' limb that laid down on a tile roof still attached at the trunk, that I decided to use as a training day with the crew .The only damage that occured and remained whenn we left was the initial two tiles that broke from a from a four inch stob wich kept the main limb and foliage from tearing off half the tiles.
Another 30' limb that stretched out over the house I took in one shot. It was probably 10" in dia . The only reason I was able to do this particular Limb in one piece was beacause of the Grcs.
With a Hobbs as good as it is, I could never have kept the continual pressure and height I needed to keep it from dragging tiles off the roof.
With all the lowering devices we have I still trade off when rigging. Sometimes even the basic wrapes on the trunk. I like to get the guys on the crew aquianted and proficient with all aspect of lowering devices.
Thanks
Greg