re: Antminer name, no problem. It is very common for various posts, articles, and videos to mistakenly do the same thing because the authors just don't care about being correct. In my book that raises questions about what else they may get wrong The other even more common error is calling every crypto coin "Bitcoin". Only BTC is Bitcoin. All others are generally called altcoins and in this part of the Forum, crapcoins...

Those are good prices you were quoted, just be sure that it is a reputable dealer you are working with. Personally I don't have any of the M21 series but I do talk with several miners in the pool I use who do have them - overall they are quite happy with them.

Given that both MicroBT (Whatsminers) and Canaan have very good products to me it would boil down to what happens if something breaks: Generally the Whatsminer's need to be sent to China for repairs. Canaan's Avalon miners on the other hand are modular with components that are easily replaceable by the user. After sales support from Canaan is excellent meaning once you work with them to diagnose a problem they will quickly send you the replacement part for you to install.