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Originally Posted by yagon
An issue for some people (myself included) is cooldown time: a refractor has a short cooldown time compared to CATs and dobs.
My observing tends to be for half an hour after work during the week: very casual. If I had a CAT I'd observe half as often.
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I am not sure about shorter cooling time of the refractor.... The tube of the refractor is closed on both ends, so there is no air circulation to help cooling down... Of course, if the tube is made of metal (usually the case for older instruments, I am not sure about these days), that may be advantage over cardboard or fiberglass tubes usually used for reflectors.
On the other hand, the reflector, having a tube open at both ends, should reach thermal equilibrium faster, but because the mirror is usually much thicker than equivalent lens, it will take more time.
So, all this depends on many details of the design of particular instrument.