The other day, I posted about two popular emerging market ETF (EEM, VWO) choices. While you aren't likely to go too wrong adding one of these two major ETFs to your portfolio, I believe you can do better.

The three choices I examine here are all fundamental analysis ETFs, rather than based on old-fashioned market weighted capitalization like the prior two choices. What this means is the underlying stock choices are chosen on a rules-based entry system rather than how fat (or skinny) the valuations have gotten. I have written about fundamental analysis systems before, including here and here.

Wisdom Tree has used a dividend-rating system to select stocks most likely to outperform. This is based on back-testing that has shown that, firstly, dividend-paying stocks outperform their non-paying brethren, and secondly, that higher yields more often than not indicate relative undervaluation. Finally, Wisdom Tree's research shows that a basket of these stocks also have lower volatility than a comparable market-cap index.

The FTSE RAFI indexes, used in many Claymore and PowerShares products, uses four factors to weight stocks. These factors aren't related to the markets enthusiasm (or lack thereof) for the company itself, and extensive back-testing has shown these type of indexes outperform old-fashioned market cap indexes, such as the S&P 500, MSCI EAFE, and Dow Jones Industrial Averages. The factors are dividends, cash-flow, book value and sales.

The three choices we are looking at are Wisdom Tree and PowerShares products. They are the PowerShares FTSE RAFI Emerging Markets ETF (PXH), the WisdomTree Emerging Markets High-Yielding Equity ETF (DEM), and the WisdomTree Emerging Markets Small Cap Dividend ETF (DGS).

Let's take a look under the hood of these choices. Firstly, cost and turnover. On cost, none of them has a significant cost advantage, with DEM and DGS are 0.63%, and PXH at 0.85%. Turnover in PXH is 8% annually, with DEM at a remarkable 3% annual turnover. DGS does not have a reported turnover, but given that this is a small cap ETF, you can expect it to be relatively high, certainly higher than any of the choices I've discussed to date.

Let's look at the average company size and some of the top sectors in each product. In terms of average company size, these are all distinctly different products. DGS defines 92% of their portfolio as small cap, with the remainder as mid-cap.