Depending upon how painful the "argument" was, I am actually reasonably impressed that they replaced it twice. Many places would not have. Especially for something sold in that manner. I personally have no experience with the company but everyone I know who has bought from them has been happy. One friend's chuck did not meet spec but he still felt that he got such a good deal that he was happy.
I do agree less likely to have problems with a Servo unit. But they cost considerably more. One can buy rebuilt ones that come with a warranty but they usually are meant as replacements and normally do not have all of the parts necessary for a new install. After you buy the necessary installation kit, the "savings" might not be worth it. My mill had a very old version of a drive that had a non-standard setup so I had to bite the bullet and buy a new servo with the appropriate kit. Import plus stand alone kit was only about $150 cheaper.
Ken
