This used to be my go to "well" mixer until it was temporarily discontinued, since to me it has always been leagues better than Bacardi Sliver either neat or mixed and where I live it is $10 less per bottle.
 On a recent Sam's club trip i saw a pallet of new Members Mark Silver rum in the same shape bottle, but with a different lable. As much as I was tempted to grab 6 cases of it on the spot to last me the next 12 years or so in case of another "shortage", i decided to grab one and compare it to an unopened bottle of the old pre discontinued rum I had stored in the basement for the last 2 years, just in case they got a new supplier, recipe, or manufacturing process for the rum.
I did a 4 way blind test between the new bottle and old bottle, as well as Bacardi, and Plantation 3 star as it is my top shelf mixer. All were neat, room temperature, and labeled, then shuffled in very classy sams club styrofoam cups. These were my findings.
Bacardi was in dead last, and I guessed it correct in the blind test. Not much flavor, but very harsh taste, not a good rumin my opinion. It sticks out in a rum and coke for sure, and though I am not a snob and will generally drink, and appreciate the alcohol I have in front of me no matter the price point, there is not much to love here
Plantation was the top end, a whole different league of flavor to the other rums in this comparison. Full disclosure, this wasn't purely blind since 3 star has a slightly yellow color to it, so I could pick it out by eye, but the extraordinary flavor is really an outlier for this test. I Would happly drink it neat or in any mix. I wish Sam's would carry it as it is a fantastic top shelf mixer and at Sams it could possibly make it below the $30 price point, but most places ive been to it is about $32, and well worth it for a top shelf mixer.
In the middle, surprisingly more toward the Plantation side of the scale than the Bacardi side was the Members Silver, both old and new. Both have a very similar profile of a simple "pure sugar cane" flavored rum to me, not "complex" but enjoyable to sip neat, and from memory its great in a rum and coke, long island, or a simple mojito. If i am splitting hairs in the blind test I did chose the old bottle as very slightly better than the new bottle due to a more "pronounced and strong flavor", though that really could just be down to a slight batch difference, being stored in my basement for 2 years, or of course "user error". They are really too close to call though in terms of quality. I did multiple blinds between just the two, and I would generally pick out which was which, but some sips I perfered the more mellow newer bottle, and others I perfered the slightly richer characteristics of the "aged bottle".
All in all if you have never had it before I highly recommend giving it a try, and if you were a fan of it prior to the discontinuation like me, I would certainly recommend going to your local sams and grabbing a bottle, but needless to say, I will be grabbing a few cases myself.
P.S. sorry about any typos, I am writing this after blind testing 4 different rums!
Customer reviews for Member's Mark Silver Rum, 1.75 L for