In order to determine which is the best IDN Domain Name value, we need to look at a number of variables.
After some consideration, I would say that in most languages the ccTLD extention would be in most cases somewhat more valuable.
However, in some cases, such as Geographical domain names, I feel the .com, and transliteration, which will be included in the ownership of the .com , will be more valuable. The reason for this, is it just fits better, and also is not reserved or regulated by the Government where the ccTLD resides.
This would cover most languages, in my opinion.
As, far as the Arabic, and Indian languages, are concerned, I would have to go with the .com version.
In the case of Arabic, because there are so many countries that speak it, the .com would have more connection with the population, as a whole.
This may also be the case, with the Indian Domain Names, as there several different dialects, used within the overall population.