American Alternative Insurance Corporation good?

[Richard Snyder]

My insurance agent suggested liability umbrella over my vacation rental property, "life," and my single family long term rentals with American Alternative Insurance Corporation.  They are rated A+ on Best but google reviews terrible.... i mean really terrible.  I have already discovered they don't answer their phone, don't have website account access and don't take credit cards.  But their rates are so good. Anyone have any experience with them?  Anyone have companies they like that can offer a liability umbrella for everything: day to day life, vacation rentals and long term rentals?