@ Blake
Sorry, for the delayed reply, I’ve been dealing with bugs relating to the latest release and WP 4.0. I’m prepping the bug fix release so the niggles should all taken care of.
No I have not, but they’re all best of breed plugins. The tough part would be integration. I can not speak for the others, but Connections presently has no integration point with those though I think GravityForms and EventEspresso do have MailChimp integration.
There really should not be any conflict between WordPress CRM and Connections as Connections does not use the WordPress Users table (assuming WordPress CRM does). Connections only adds a meta field to the user to link a user account to a Connections entry (with Link)
If you need some sort of integration of Connections with these, Connections does have many actions and hooks available so you could have a dev create the integration you would require. If you go that route and the dev needs a hook in a specific place, I;d be more than willing to add that hook if it makes sense to.
Any way, I hope that helps!
