I have always been told that the only same plane rear sight was the Ashley same plane rear.  I have always been told the Trijicon rears are set up just like the A2 sight (200/300 apreatures) but had larger openings and the large aperature had tritium.  

Now I am being told that trijicon is saying the rear aperature is a same plane aperature.  Can any of you with Trijicon rears tell me if you have the same POI with both aperatures or is it set up like the A2 aperature?

Trijicon rears are just like the standard a2 rear 1 big, 1 small, big one has the tritium lamps as you said... far as I can tell they are exactly the same size as standard a2 rears (aperture size). Purchased a set about a year ago, I do think the front post is a little bit too wide though.[:\] They may have changed from the a2 aperture since I bought mine but I doubt it....highly.

(edited to add) - sounds like someones trying to sell you what they happen to have in stock... id stick with trijicon or mepro

I certainly bow to the expertise of many here, but for what its worth, this is an e-mail response from Bushmaster re the same question on the Trijicon (CP-25) tritium sight set they sell as opposed to a standard A2 aperture.

"       Yes, there is a slight elevation shift between the A2 apertures. The Trijicon apertures are on the same plane so the large aperture with the tritium inserts are used for low light and close distance. The larger apertures are used for close distance as it is easier to pick up a target quickly especially if it is moving. Six o'clock hold is recommended at any range. The smaller apertures are used for distance and more precise shooting.
           Thank you. "

I have two of these sets and like them very much. I particularily like the adjustment feature on the front sight. (also have an ARMS 40 and KAC 200-600 BUIS - all seem to be high quality  products)