Cult report.
Quick update on the SIT David Ellefson series I just bought and put on the NR. They are NPS, they feel as good as any round wound I recall playing (except TI Jazz Rounds, which are really small strings with small windings). I have not used them live or in a band setting yet, so this is simply impressions from home which may or may not produce equally well live. I have a med set and they don't feel stiff to me, and I don't care for heavy or stiff strings. The lows seem big without sounding hallow, the mids are thick and full bodied, the highs are very present but not clanky sounding--but this bass is on the dark side, so I would expect them to have even more nice sounding highs on other basses. They replaced Roto 66s (different animal I know), and sound bigger and more even across the freqs. In fact, they seem to be well balanced in that respect. Some rounds seem to have a definite focus on a certain mid freq, but these seem to have all the mids nicely balanced, making for a beefy sounding string without being dark or lacking character.