Benefit of a Newer (Used) DAC - "Bang for the Buck?"

Despite having a SO who fails to understand why anyone would spend more than $100 on a “radio,” I’ve managed (over several years) to covertly assemble a fairly decent home audio system.  (My prize acquisition being a $500 set of LN Belle Klipsch loudspeakers off CraigsList).

At any rate, relying on quality used equipment that is past its technological “expiration date” has, under the circumstances, served me reasonably well. However, I’m now to the point where I’d like to (again) update several components – namely, the DAC.  

I’m currently running a Cambridge CXC transport through a Genesis digital lens and a Muse Model Two DAC – both of which, while fully functional, are fairly dated.  Realistically, how much noticeable impact can I expect from a newer (used) DAC – like a Bryston BDA-2 or MHDT Pagoda (for example)?  FWIW, my current setup does everything I need it to (i.e., play Red Book CDs).

In advance, thanks for any advice/feedback.

The RME is a killer DAC....its really an amazing unit.   Although it has a very good headphone section I use it as my systems DAC.  All of my digital sources go to it.   I listen to phones with the RME as the source and the Quicksilver headphone amp.  

It is really hard to beat for the price.  What I like about it is it's ability to connect to anything without a driver.  Plug a phone, tablet, or computer and it recognizes it immediately.    Its not cheap, but its far from expensive in the context of what some dacs cost.   Worth every penny
I am sold. Even new it's not too bad. Seeing it for as low as $1,150.
I can second the Denafrips Ares II.  I have considered most of the DACs mentioned in this thread and decided upon the Ares II.  I like it so much I have a Denafrips Pontus on the way to me right now.  Check out the reviews for the Ares II.  Many of the DACs mentioned are very good but the R2R Ares II does it for me.  
All RME ADI 2fs owners really need to spend the money and throw out the switched power supply and get a linear supply. The very first evening with my RME I switched out the power cable with one I built with Furutech plugs and cable I purchased from VH Audio and was pleased with the improvement; was the PC I was already using on my Bluesound Vault 2 so I ordered more parts and built another.  Was probably a month later I was watching a YouTube video off Kevin Deal on the Sbooster supplies and made my mind up to change out the PS regardless of what the manual claims as it will not make a difference. After researching a little I settled on Teddy Pardo from Israel. Shipped to the States only took a couple weeks and with shipping it was under $400. The improvement is well worth the cost, actually a bargain and a must in my opinion. With the Teddy, the RME is more open, stage greatly improved in both width and depth. The bottom end even with the switched supply is very good, but with the Teddy it digs deeper and tighter. The sound overall is fuller more open, lower noise floor with greater PRaT. It’s just hands down superior with the Teddy

 I run mine balanced out with Nordost Frey 2 and PC is a WyWires Silver Juice II Digital Series. The combination of cables and Teddy on the RME is very natural, not at all bright or fatiguing. Top end is exceptionally clean but not bright, or soft, but honest. If you’re looking for a DAC to roll off the top end or color things then this is not it, but I suppose pick another filter and mess with the EQ. and you’ll can get there. I run the Sharp filter and don’t mess with the EQ and find it’s not at all bright, edgy, or exaggerated running direct. Can’t give the RME with Teddy Pardo enough praise.
I own a Topping and it is quiet, high clarity very dynamic, no rolloff.  I paid 630 for it with price match and 2 year warranty.  Apos Audio has several brands.  30 day return policy.  Schiit is another company.  Starting at less than $200.  Their units come delta sigma or R2R.  So in short lots of new and used for your choice.  If I changed brands, I might be inclined to try one with tubes such as the Tubador.  This would pair well with your speakers.  PS.  I too have horn speakers.