When I had just one REL R-328 I connected at my 250 DR for a while, but when I learned that isn’t advised without using the Naim-specific REL Bassline Blue cable, I changed to connecting at both speaker terminals. I had to remove a bit of the sheathing on the standard REL cable to reach both speakers, but that ended up sound better anyway.
Now that I have a pair it’s easier and more tidy to connect at the speaker terminals. Now I have a 1.5m pair of regular Bassline Blue cables for that (although the standard REL cable works too).
NDS. To much good stuff told about NDS so let’s see what it can do with my 555PSDR on it. Will add my NDX2 on it as a streamer only and compare against Audirvana UPnP straight into the NDS
Won’t keep both. One has to eventually leave the building If just for the streamer in ndx2 one might as well get ND5XS2. Having lived with Lumin U1 mini in the past I also very much enjoy the synergy between that and naim. Many ways to audio nirvana
I’ve recently upgraded my XPS DR to a 555 PS DR to power my NDX2, and also swapped out my 250DR for a 300DR. Both been very nice upgrades. The most surprising change was my latest purchase of an ex demo SSD drive Melco N1ZS/2EX which replaces my NAS as the source. The Melco has made a massive difference. So much extra detail through base, mids, and highs, it’s been astonishing. I felt it was a little on the bright side for my taste and as an experiment I swapped out the standard mains lead for a spare Power-Line and that has brought balance back to my system. (Who would have thought a power cable could make so much difference). System now sounding outstanding.
I swapped out my ageing UnitiServe for exactly the same Melco model as you and can only echo the improvements you enthuse about. I was shocked by how much difference a quality server can make, and the UnitiServe was no slouch.
I put a spare PowerLine on the Melco and yes it does make a rather positive difference.
Funny that there’s a few here who still believe that any NAS can provide the same quality that a proper music server can. They obviously don’t know what they’re talking about or have never compared the two. According to every review I’ve ever read it clearly does make a difference.
If just for the streamer in ndx2 one might as well get ND5XS2. Having lived with Lumin U1 mini in the past I also very much enjoy the synergy between that and naim. Many ways to audio nirvana 
that’s the plan!