xJownage I agree with the need for a more objective standard for suspect reqs. Out of curiosity, what do you think of my idea of requiring a high-ish level replay of the suspect in question in addition to normal reqs? I honestly think that the TLs had the right idea in that simply good at laddering isn't enough to be able to determine whether or not something is uncompetitive, but they just need a more objective way to understand it. I asked myself this when I came up with the idea: "Do I want someone who has never used mega mawile or aegislash or baton pass making the decision on whether or not it belongs in the tier?"(those were suspects I personally participated in). I honestly believe that you simply cannot understand what a pokemon or move does unless you actually use it yourself, even if it's "obviously broken/uncompetetive" like OHKO moves, evasion, or Mega Salemance (for OU, mega dragon should be fine here obv). This goes double for more subtle aspects of the metagame whose potential power/uncompetitiveness is much more subtle like Deo-S or Shadow Tag.
As for COIL, I highly recommend taking up a discussion with
Antar, but allow me first to stage a brief defense of the rating system. COIL is a logarithmic function(this one to be exact:
C=40*
GXE*2^(-
B/
N)) based on number of battles and your GXE. For a given GXE X, COIL will hit an asymptote of approximately 40 * GXE after about B * 10 battles (e.g. for a GXE of 60 and a B of 40, it will take about 400 battles to hit 2600, give or take 50), and for all intents and purposes stops rising there. Given how a logarithmic function is shaped, a higher GXE will allow you to surpass this asymptote much, much faster.
The main difficulty of the COIL system is that it requires TLs to essentially predict the "baseline" GXE for players they deem competent enough to vote. It is a well known fact that the longer a ladder is up between GXE resets, the more the average GXE/ELO will inflate as more players start playing the ladder. Most suspects last about 2 weeks, but this one lasted for far longer, making it reasonable that the uber TLs underestimated the COIL needed to distinguish "competent players". Compounding this is the fact that the ubers ladder is notorious for attracting bad players, which magnifies this issue even further because there is a fairly solid base of really awful ladderers to further inflate the average GXE. This issue can be adequately resolved by simply raising the COIL requirement and/or reducing the suspect test length.
Addressing your second issue is a bit harder though, as you're basically saying that it takes too long for skilled players to hit the GXE requirements. This would imply that the constant B was set too high by the TLs (lower B means fewer battles needed to asymptote). Lowering B would basically encourage players to not stay on any one alt too long and switch alts often to try and get the win streak needed to obtain reqs, while making it too high brings about the problem you mentioned. Obviously, the length of the suspect test also needs to be considered when determining this value.
So yeah, that's the COIL system in a nutshell, along with the cause of the issues experienced by players and the methods for fixing them (please please please yell at me if I got any of that horribly wrong). I don't think there's anything wrong with COIL itself, but it does require TLs to both have a good head for mathmatics AND have a good idea of what the suspect ladder is going to look like. Setting all the right variables is pretty difficult to the point where it's borderline arbitrary, but that's probably going to be an issue no matter what rating system you use.
Proof that COIL is perfectly capable of weeding out lesser players:
Antar's (probably better) explanation of COIL:
http://www.smogon.com/forums/threads/coil-explained.3508013/