Glad to hear it arrived safe and sound! I think this is a good introduction to what you'd normally expect from a NOS R/2R DAC, and it's priced well. The TDA1543 chip was a budget chip in the Philips lineup, so harmonic distortion is relatively high, and accuracy/linearity is not going to be the greatest (this ain't no Yggy). In these regards, it probably sits around or below the rumored chips used in the Metrum DACs, and Metrum has multiple of those per DAC (TDA1543 might also benefit from parallelization). I think it's safe to expect some limitations as such, but you can often find these for $175-250 depending on if you bid or buy. I think they're a good option at that price point. DACs using TDA1543 chips at higher price points make me a bit wary.
So, if you don't like a warm, smooth, slightly thick, and not very resolving sound signature, you may not like this DAC. If you haven't liked any NOS R/2R DAC you've tried or found them to have certain undesirable traits, this won't change your mind. I think it does very well with liquidity and general tone, despite being a touch thick and intimate sounding - perhaps more so than the Metrums, and is just downright enjoyable. Others are likely to disagree. I can't argue with what personally draws me into the music.
Burn-in might help improve the sound over time,for those of you that think that's possible. I do think it sounds best after warming up for a bit at least. I don't believe these chips are designed to be left on all the time, though, for longevity reasons. I'm also not sure how well it scales with better and better SPDIF sources, but that's a factor to consider as well.
I use mine with this PSU, which is supposedly linear (I can't verify): http://www.amazon.com/Super-Power-Supply%C2%AE-Transformer-5-5x2-1mm/dp/B00DHMCNOO/ref=sr_1_7?ie=UTF8&qid=1426029711&sr=8-7&keywords=linear+power+supply
This PSU might sound a bit cleaner than running it off the battery. Maybe. Likely fooling myself. Too slight to really tell.
One odd design choice, IMO, is that you have to leave both the "mains" and "battery" switches on while plugged in if you want to charge the batteries. Oh well, no biggie.
Looking forward to hearing more thoughts as you give it more time, especially directly compared to the Octave MkII.