(First off, I just want to give major props to Brian @ Best Bass Gear, and the customer service at Nordstrand)
Recently, I was looking to "upgrade" my SR5.
Now before the EBMM people blow a blood vessel.....
My SR5 came used with a Duncan preamp and Duncan pickup.
*now you EBMM people can blowup....since gutting a Stingray is blasphemy

*
Anyway, I dug the bass a lot but couldn't get the tones I wanted or expected.
I decided that since I liked the SR5 so much, it was worth dropping some coin on "better" components.....or at least get closer to the classic stock 'Ray tone.
First I decided to replace the pickup. Since I automatically assumed the 2 coil Duncan was "meh". The Nordstrand MM5.3 seemed like the perfect replacement. So I ordered one from Best Bass Gear....since they're rare used. Got the MM5.3, and installed it.
It did not function properly. After some research, the SD preamp was not intended to be used with the 3-coil pickup. So I just shelved the MM5.3 for a few months. Screw it. Too many gigs to have a bass out of use.
Anyway, so I started to favor a J bass for a while, and thought it was a perfect time to figure what the heck was up with the SR5 and the nordy. Re-installed it. Still wasn't functioning right. Low output, etc.....
I thought it was the preamp. Since the SD site specifically says not to use it with the 3 coil pickups.
Since I wanted to replace the SD preamp, I decided to order the John East MM preamp.
Got the East preamp, and installed it with the MM5.3.
Still wasn't working properly. same symptoms as before.
Contacted Brian @ BBG and he told me to test it directly to the jack.
Did that. Still not right. Series mode didn't work at all. Still low output.
He advised me to send it in to Nordstrand to be tested.
Sent it in and waited.
In the mean time, I put the SD pickup back in.

Wow......sounds great!
Works with the 3 way switch as it should.....full output!
Gigged with it for a while. couldn't be happier.
I get the call from Nordstrand saying my pickup was tested, and it appears to be 100% functional. What the heck!?
They send me a brand new one, just to be sure.
Cool.
Eagerly await it's arrival, and install it the day it arrives.
SAME THING! low output, and sounds like crap.
Call Brian @ BBG again.
Sent the pickup back to him, and he tested it.
He found the same issues I did, and contacted Nordstrand himself. They discovered that something wasn't right, and could possibly discontinue the MM5.3 because of the constant support requests. (I'm not downgrading Nordstrand at all, as an engineer, I understand)
So in the end, it was decided that they'd just send me a MM5.4 instead.
perfect. I just want my stingray to sound good, and work in all 3 switch positions.
At this point, I was still gigging with the SD pickup and East preamp and digging the tones.
Get the MM5.4. Wire it up.
First thing I notice is the lower output. The tone is good, but much lower output and slightly muted. I was worried about the MM5.4 sounding dark, since it features the hum canceling design. It's really not that dark, but darker than the SD pickup.
Actually, I would say the Nordstrand has a lot more fat low end to it. In a vintage way. The Nordy is very vintage sounding.
I've never had the opportunity to play a vintage Stingray, and I'm sure the way I'm using my SR5 is much different than most......so I cannot compare.
Obviously my preamp settings changed a lot from the SD to Nordy. I was bumping up the lows and mids a lot less. kicking up the highs more than ever. With that you can note the differences between the two pickups.
My point is, I think I prefer the ceramic SD pickup over the alnico Nordstrand pickup. Not the outcome I had expected.