I've been using the BDP-105 in a 2.1 channel speaker rig. It's not a bright DAC. It may be relatively bright but by no means harsh in the treble. The bass is tight, well-controlled. If that's lean then so be it but it works for me and for my musical tastes. Bass is good for me but I use a sub. I imagine tight bass could be to the benefit of some headphones with bloated bass. I will try the T50RPs with the Oppo when I have time in order to access the weight of the bass on headphones.
It's my first Oppo device so I can't say how it compares to the earlier models. I haven't tried the headphone output yet. Been primarily using it via USB to SPDIF. I will get around to buying a longer USB cable so that my computer can reach it.
By most opinions on the AVS forum the BDP-105 is a substantial upgrade over the earlier models but then one man's substantial is another man's yada yada. One poster mentioned he liked the 105 much more than his 83SE.
http://www.avsforum.com/t/1439524/official-oppo-bdp-105-owners-thread/420
I'm pretty happy with this unit in terms of general characteristics like soundstage, detail, clarity, etc. Build quality is very good and it should be at $1200. It's a keeper in my opinion but for those of you with the older models it is a harder decision. It's an evolution in their product line with some features that not everyone wants.
I wanted a good blu-ray player for my HT rig that could also serve as an excellent transport for digital audio and play CDs for my 2 channel speaker/headphone rig. Stick a fork in me because I'm done for at least two years when the vicious cycle begins again.
The Modright mods look interesting but I agree, just buy a tube CD player if that's what people want. If I decide I want to try a SS amp I don't want my source being affected by a tube mod. I do hear they will do a non-tube mod as well to the BDP-105. Do I need a >$2K blu ray player? Do I need any of this is what I ask myself everyday