I don't stick to one brand at all. When buying a power tool of any size I look at all that I believe might be good candidates for the application in my shop and then pick the one that seems to be the best fit for the need and most likely to be easy to get replacement parts and service for. A great high dollar tool that you can't get parts and service for is not a good deal at any price.
When buying smaller hand held power tools I do similar, but look for reputable brand names and then compare features and ease of use. As a result I have many different brands of hand held power tools. One brand may be best for their drills, but not so great with their routers, etc. so I buy based on who makes the best that also fits my needs best. With these, if you can get 5 or so years of use out of them, it doesn't matter so much if replacement parts become un-available. There are likely better designs available by then, so I just replace with the best available when the old one is no longer serviceable, sometimes staying with the same brand, but sometimes switching brands. For me, it always depends on who of the better brands is making the tool that best fits my needs and is the most reliable. I don't ever buy the most expensive, unless it offers something that is so much better that the others that makes it worth buying. I have Leigh Dovetail and FMT jigs for this reason, but I don't own any "Green Kool-Aid".
Others may not agree with me and that's OK with me, but this is how I do my woodworking. Please don't try to change me.
Charley