Fucking TERRIBLE. Don't do it. I worked with Funded Today a few years ago and they literally stole $4K from me. All the 'publicity' they got me ended up being dead links to websites they built. I called them out on everything and they went back and deleted all of their Skype chats. I took screenshots before they could.
From my experience, these groups only work IF you're already doing well. Essentially, they're just FB marketing groups. So you're going to pay a ton of money and then they'll handle FB ads for you and everything else they do is either fake or just kinda pointless. They'll add you to their 'home page' too which basically gets 0 views.
Altogether, don't do it, unless you already have like $50K-$100K+ in donations.