I have two MagnaSine inverters, 12 and 6 y/o.. both work flawlessly. Using one to power a pump/remote 'powershed' and the other pumps, freezers, etc in barn. No problems.
I will never buy anything from Signature, they remind me of the dot-com marketers. Asked a couple questions, weeks went by to only get a sales pitch on their product line, not surge capabilities. Took 4 weeks to get another non-answer about Veterans discount when I replied rudely I finally got an answer (which was not that unusual a response for documentation) just to confirm what Signature required.
I have a local MagnaSine distributor who still puts them in lot's of installations where the HF inverters fail.