The Optima Chrome 4099 RL set I purchased (brand new, btw) played with a more-than expected muted sound on the E and A strings (which was OK), but a completely opposite bright sound on the D and G strings. I too was expecting these strings to be somewhat like the original Ric type flats. I am not saying that they do not sound as expected. I am saying that the set I have played unevenly. Whether they were dull and thuddy or somewhat bright, at least I could use them if all four strings played similarly.
Pros - Smooth feel,
Well made silks, resistant to a lot of handling
Polite, middle of the road sound scooped at the right places
Can be used in a vintage and modern context
Moderately stiff, but not overly hard on a bass neck
Lots of mid presence, polite but very present bottom, attractive upper click for clean percussion
The volume and tone is more consistent than a lot of other flats I've tried
Cons - Pretty Expensive
Hard to find in North America (well in Canada, at least)
When new, very zingy and G string can be twangy
The review is pretty much in outlining the pros and cons of these strings. I purchased them second-hand thanks to Dannster for 35 USD (before the Canuck Loonie took a dive) I don't regret buying these, but I don't consider them to be the best value strings.
They're certainly great sounding strings and are quite versatile flats that, like Chromes can be used in many different styles. I do find them better than Chromes, though. In Europe, they are considerably cheaper than on this side of the pond, so for our European brothers and sisters, these might be the flats you'd be looking for.
I made a video reviewing them if you like to watch a dilletante on the bass make a fool of himself: