But, It should be better.....!
Since SATA 300 is backward compatible with SATA 150, and in theory at least, should be of higher quality (more bandwidth, introduced by lower losses), Why return it at all?
SATA 1 & 2 are the same physical configuration. So, if they're (the maker) not lying about it's capability, then the only thing to consider is length and color. Well, add to that how much you're willing to pay for it.
Newegg's site offers a direct comparison via selection check boxes and a "compare selected" button at the bottom of every page.
As to Newegg's specs being incomplete, every product on their site is linked to the the manufacturer's product page (for that particular item). If there are omissions or errors it's usually not their fault.
Since the original poster seems unwilling to accept an upgrade to SATA 2, it does seems likely that introducing SATA 3 dialog could only cloud the issue further.
And finally, Mr thrudd, "As too SATA, SATA2/SATAII/SATA-150, SATA3/SATAIII/SATA-300". I'm sure you meant "to" (the preposition) and not "too" (the quantifying adverb). Please accept my apologies for mentioning that, I struggled with it, but unfortunately the dark side of my character willed out.