Model that a lot of saas seem to use is:

put your consumer marketing site front and center at x.com

sub-brand your enterprise offering, and have a section explaining it, i.e. x.com/pro

this way you're maximizing your seo juice and consumer reach

the actual apps themselves can live on a subdomain, i.e. app.x.com for the consumer and pro.x.com for the enterprise

if/when the enterprise version really takes off, you could always rename it something unique if desired