OP, you didn’t say whether your project is covers or originals and whether you’re performing in public. It matters because if you are, the audience may have a perception of what the band should sound like that might affect your choice.
If that is not the case, my view is that the most important thing is to play what makes you want to play. Differences in tone between roundwound and flatwound strings are waaay more important to bass players than to people who listen. So make yourself happy.
A couple viewpoints on string choices:
Chromes are flats. They don’t sound like rounds to me, they sound like flats. They feel exactly like flats. They are a bit brighter than some others.
EB Cobalts are awesome strings, they are extremely bright flats that actually can create a passable roundwound tone. The rumors are true there. The problem with them is the construction - they leave tiny spaces between the winds, which helps create the tone everyone loves. They also create the friction stickiness people talk about here. It’s definitely a thing, enough of one to get them off of my bass after a couple gigs.
D’Addario Half-Rounds are unloved around here for some reason. But I’ve had a set on my six string for 8 or 10 years; they are a nice, bright flat that can sit in a mix like a round. They are also sticky, like Cobalts, because of the process they use to grind them down. I think it leaves microscopic burrs on the string surface. Unlike Cobalts, the effect goes away after 10-15 playing hours. John Patitucci uses these on his electrics. Don’t sleep on these.
Pressurewounds are fantastic strings. I love them. They are absolutely roundwounds in tone and feel, though. Just maybe 25% smoother to feel than other rounds. But they do not sound like flats, at all. They sound like slightly broken in nickel rounds. They also sound great dead. I use these on most of my basses.
