The difference you're experiencing is in the stiffness/flexibility. The BNs, being round-core, do feel slightly more supple/less stiff than their hex-core counterparts, although they're not quite as loose-feeling as some of the round-core strings by other manufacturers, such as DR.
Also, the Balanced Nickels are, well, balanced tension.
A typical set of bass strings has much higher tension on the A and D string, and much lower tension on the E string.
Thus, if @p12bassnut plays the A and D strings more than the E string, the BNs might feel floppier to him than a standard set of 45s.
However, I agree that the round core makes BNs feel a bit slinkier than a hex-core string. (I like the round-core feel, but opinions differ...which is why there are so many kinds of strings!)
My solution is to play slightly nearer the bridge for lighter strings. The closer to the bridge you play, the less the strings move and the stiffer they feel. It changes the tone, but so does using different strings.
Am I right in thinking that the regular Boomers have only one wrap on the G string, but that both RC Boomers and the Balanced Nickels have two wraps on the G?
I'll wait for @Jon Moody to answer definitively about the Boomers, but you're generally correct: most strings have one wrap on the G, BNs and RCBs have two. Also, most low B strings have
three wraps, and some E strings also have three wraps...but the BNs and RCBs have two wraps on all strings, regardless of size.