I also think it is fine as it is. And the process of appointing senior members is clearly excellent - read almost any post by a senior member and you will appreciate why they have been selected.
For example, I noticed today (perhaps belatedly) that ajaxfetish has been promoted to Senior Member. When I joined the .org, he was among several people that made me feel very welcome, explained things, supported my stories and thoughts in the Main Hall and whose posts I always read with enormous interest. He epitomises the spirit of the .org and I knew I had found a place I would like to stay. Yet he has only some 550 posts.
His promotion is well deserved and demonstrates to me that the existing system is exactly what it should be.