I can't speak to the Labella string pref. as I've never tried 'em. I love the D'Addario chromes/105-50. Great old school "note fundamental".The note decay (thud) isn't as quick as Fender flats, for example. If you think they're a tad bright when new, just roll off the edge w/ your bass passive tone. Remember they'll sound a bit brighter on a maple f.bd. than a r.wd. I like to experiment w/ thickness & width of real sponge or foam rubber to dampen under strings @ bridge.for when I want the extra "thump" that sits well w/the exquisite "P-Bass w/flats" sensibility. I think they have PERFECT tension, but you gotta lower the action compared to the rounds you're used to.(generally), for "feel". You can dig in & really make the notes "pop",or lay back & still have great tone. PS: Sadowsky has beauty flats in a 105-45,which are slightly less stiff, but have a nice growl if that appeals to you, & superb tonal balance. (lighter ga. also avail.) *See followup below.