These strings are great if you like a mellow "broken in" tone from your guitar. If you like a bright, crisp tone you should avoid them. The low E-string in particular is VERY mellow sounding.
I love the sound I get from these strings on SOME guitars, particularly for strumming when I don't want the kinda harsh, metallic, ultra-bright tone that some of most popular acoustic guitar strings deliver. But I primarily think of these strings as suitable for strumming, They can be a bit too mellow for fingerpicking on most guitars, at least for my taste.
Apart from being a bit hit-or-miss depending on the guitar and your style of playing there's also an issue with quality control. I've had several sets with RUSTY and completely DEAD (rather than just mellow) strings. Not good! Pyramid should really consider using sealed packaging as rusty strings is something I've experienced with other Pyramid strings too. Which is a shame as when it comes to TONE Pyramid make some of my favorite strings!