Approval Service.

Anyone else use a approval service and if so what one and why? I just started using one and so far not to bad. Most pre 1940 items F=VF centering and LH or NH. Pricing averaging about 40-50 percent catalog.
So who do you use and why? Looking for airs before 1961 or classics in Central America.

I have used Geographics in Easton, CT, for years for classic, pre-1940 world wide and am very satisfied. Most are F-VF and LH-H with some NH. An occasional thin is received and I usually keep it as a space filler and so note on my album page. I do not use them for US stamps. They tend to Europe and British Colonies and some mid-East; very little South or Central America and almost never Africa.

Donald