I have joined the Merit network since the idea is in itself quite mind boggling. The mission of achieving a more effective decentralization than most of the other coins out there through a system of invitations is great.
However after having joined the network I'm having a few doubts. First I had to beg for a few invitations which I could use to convalidate the invitations I would make for my friends. Then, once I've finally managed to invite two friends whom I could validate, now I am unable to supply them with invitations that THEY can use if the want to invite anyone. In other words, the growth of the network in my direction is stuck and so it will probably stay, since we won't spend our time begging for more invitations because we are not beggars, and if it has happened to me and my friends that would probably apply to most of newcomers. Of course, beggars will possibly succeed in getting more invitations, in which case the system is likely to select a population of beggars, not the kind of community I'd like to be part of.
This means that once again early adopters got too much advantage over later adopters, which is the same paradigm of Bitcoin and the other coins - in other words the mission of a better decentralization will probably not be achieved by Merit either.
If I'm wrong I'd like to hear why. If there is no smooth way to allow me and others to perform the "Proof of Growth" without having to beg, then such growth simply won't happen.