This is one of the reasons, not often discussed, about why it is that a certain redundancy in your gear is a good idea. It means you can busy yourself with other things.
--had a Losmandy Titan go back to Hollywood General Machining it was gone for about five months
--C8 OTA sent to Celestron, it was gone about two months
--AP900 sent back to Astro-physics twice, gone a few weeks each time, what was annoying was returning it the second time because issue was not fixed the first. (It's been terrific ever since.)
--Vixen 102 sent to Japan, total time gone about 6 weeks. I figured that would be longer.
I am at an enviable point where I can take a "hit" to any one major system (mount, tripod/pier, OTA) and still remain active in the astro-world. I am also aware that this would be very difficult to achieve for some people.
But if you have the funds, and if you sort of plow in $1,000 to $2,000 a year into the hobby you well might, after a while you will have some system redundancy.
So here's my piece of advice: If you're moving to something brand new, don't sell the old until you have the new thing working the way you want. And if you have something that works really, really well, and does everything you want it to do, then consider keeping it for the long haul.
When I first got the AP900 I thought about ditching the G11 but was glad I didn't because the AP900 had to go back to the factory. After it came back the second time I thought: well let's just wait a while. As a few months rolled into a year or two I realized that I didn't need the money and that, to my surprise, I continued to use the G11 quite often as my "light duty" mount while keeping the AP900 for the C14. And thus was born my venture into system redundancy. With a c8 and a c14, and several apos, I'm in business one way or another.
As I said above, this is not within everyone's means, but I bring it up here because it really lowers your blood pressure quite a bit if the equipment out for repair isn't THE ONE AND ONLY and you're MISSING PRIME TIME SKY because it is away getting fixed. You just sort of figure that rotating a piece of gear to a shop from time to time is part of the overall system of owning and operating scopes.