Whenever you make any purchase, you're also purchasing service from the vendor. So if you're going to go with a vendor that doesn't have much of a presence in the market (via R&D or long time standing or a brick and mortar location) it's likely they've done little testing of what they're selling and also that they're not stocking the parts. So returns/exchanges and general service expertise could also be hit or miss.
In the case of this vendor they're acting as a middleman to arrange drop shipping from distro centers around the U.S.
https://www.coilovers360.com/pages/about-us
The advantage might be lower prices by a small percentage. Also service could be great and boutiquey or horrible if they're just looking to make a buck with a website template and the aforementioned bad return/exchange experience.
It's all about what matters most to you.
As @
Clipdat mentioned. The board vendors are generally 9/10 service and have loads of knowledge. I've bought a lot of stuff over the years and most of them I've dealt with have been pretty great.
http://www.ft86club.com/forums/ad/ad_thesponsors.php?sort=name