I agree, there are not many X13 choices right now. If all that matters is profit, then I guess taking a shot with ONYX is worth the risk, considering the lack of options. I did very well mining CNL myself. I'm just starting to become concerned with what supporting all of these coins is doing to alt as a whole, and I think a lot of others are as well. I noticed that a lot of the other pools that normally jump all over the new coins are steering clear of this one. ipoMiner has been very respected in the community, and a lot of miners (myself previously one of them) looked to what you mine as adding legitimacy to a coin and seeing it as a good one to get in on early and hold for long-term growth.
Perhaps that's where the confusion is at: our intention has never been to advise or support a long-term investment strategy into coins we select for mining. Our coin selection is, and always has been, aimed at generating more profitable short-term returns.
Some coins we mine will undoubtedly do well long-term, but it is incredibly hard to predict which ones will. It is hard enough to predict short-term successes, which we do well at, but any sort of longer-term predictions are nearly impossible in this industry.
I've been around coins for quite a while, and there have always been scams in altcoins. There is currently more attention being drawn to them because the nature of the scams are changing to be more dangerous, with several being totally hidden, wallet-based scams (USB and ELITE both were).
As far as other pools adding ONYX goes, TradeMyBit has also already added it.
But beyond all that, the only way to earn higher returns is to take risks on new coins, which has always been our strategy. We do our best to research coins, and have been either lucky or good thus far at avoiding many of the most serious scams (NJA, for example). Occasionally coins don't work out as we might all have hoped.
Many coins that do well later on do not look like the most ideal candidates at launch, interestingly. QTL is a recent example that has a similarly large premine, but the developer has not dumped it, features have been released, and it is doing well. Some of our most profitable coins have seemed like "losers" initially for one reason or another to some people.
As always, diversification is key - don't put all your hash/money into one coin for extended periods.
(And since we're discussing the "scams", let's not forget to remember a great win we're currently seeing: IOC! It is climbing nicely.. at ~4000 satoshis now. Our miners could have gotten in well under 1500 satoshis initially, even paying at the top end of rental costs at the time.)