I'm pretty confident you won't get an answer to this question, no matter how many times you ask...
I too own a 2500BT, and I think it's a great player, especially for what I paid second hand. However, I'm in no position to compare it with, say, the current WHF high-end favourite (also a Denon), or the latest high-end Marantz and Oppo BDPs, since I don't own any of these machines.
Certainly these all trounce the 2500BT when it comes to features. Let's face it, the 2500BT is a pain to update and offers no internet functions whatsoever. In this sense, even newer budget BDPs have a better all-round spec. None of this is an issue for me, but others make good use of streaming functions and automatic firmware updates. Who am I to quarrel with them about the usefulness of these options?
There are also some forum members that claim they cannot detect any difference in terms of performance between a PS3, budget Sony BDP, and the 2500BT. Moreover, as far as I understand, WHF don't have the space to keep older equipment, so couldn't perform a head-to-head test between the older Denon and current high-end faves.
I justify ownership of mine on the basis that I paid £150 and, in my view, it outperforms any other player in this price range by quite a margin in terms of sound and picture quality (even if others argue to the contrary). Unless you want to spend the best part of a grand on a replacement, be happy that what you've got performs to a very high standard.
I think the short version of all this is: if you're happy with the Denon, enjoy what it can do, and spend less time worrying about how it compares with newer models.