I have a little insight into TAXI as a guy that has been invited to speak at the TAXI Rally a few times (I am not a member) and my manager is also a screener at TAXI.
A couple cool things I can say about TAXI:
A) They do exactly what they say they are going to do, at exactly the price they say they are going to charge you for it. There is no bull shit, no hidden costs, no hidden scams. If TAXI is right or wrong for you is your own decision, but there is no hidden scam, no hidden agendas. They perform a service, charge set fees and that is it. They do not take any percentage of any deals that they help their clients get, and there is no up sell to "premium services", etc.
B) The Road Rally is really fun and its free to TAXI members and a guest. Aside from a conference I go to on the French Riviera, its my favorite conference and if you take a buddy a long, your $300 dollar TAXI membership has just gotten two people into a really cool conference. That is $150 a piece for a 3 day conference, even if you never do anything else with TAXI. Its worth it just for that. I have made quite a few clients, friends and collaborators just by going to the Road Rally.
Some people make the mistake of just joining TAXI and hoping that alone will make them stars, which is not so smart, but it can be valuable for as part of an over all business plan. I personally know several people that have made real money through things at TAXI and I know lots of other that view the feedback and critiques as very valuable. I actually know some people who join TAXI just as a way to get people to check out their music and give them some feed back.
In regards to the screeners, they come from a wide background, and a few I am surprised they work there. Guys and gals who were A&R people for major labels. big publishers and hit songwriters. I am sure that 100% of the screeners may not come from that pedigree, but my manager who works there, before she started her own management company worked for Atlantic, Interscope publishing, and several management companies with major label rosters.
In case any one wants to discover me and make me rich....
http://www.myspace.com/venetowestrecords