Over the years I've tried different sets of strings. Thanks to the graciousness of Thomastik, Pirastro, Jargar, and Larsen (in no particular order) I've been able to experience the latest technology of string making firsthand. The strings that really made an impression on me were Pirastro's Perpetual Cadenza C and G, Obligato C, G, and D, and Larsen's Magnacore strong set. Of all the strings I've tested, those brought me the greatest joy.
Perpetual Cadenza - Rich, round bass...so easy to play.
Obligato - These strings create their own reverb... so rich! I used them for a full year with various A strings (Jargar Classic, Eudoxa, Pro Arte). These are my go-to studio recording strings, especially for chamber music.
Magnacore strong - These strings scream, "power." For my cellos, this set worked best in an uncontrollably wet hall. The strong set was especially great for went I needed to tune my C string down to a B for Golijov's Omaramor.
In looking for the holy grail of strings, tailpieces, endpins, and other toys, I came to an unusual realization: it wasn't the strings, it was the mic! What gave it away was the sound on almost 15 years of recordings. I'm not talking about the sound that I produce on the cello, which does matter a lot. Regardless of the cellos or the strings I've used in the last 15 years, there are 2 mic brands that consistently made me enjoy the sound quality of my recordings: DPA (formerly B&K) and Schoeps. The specific mics I've enjoyed on my cellos were DPA 4006 omnis and Schoeps CMC 64 (CMC 6 body with KM 4 capsule). Phones, Zoom, and other mic brands just don't do it for me; they make me feel insecure about my playing and setup.
Last year I played the same program within 2 weeks. All performance spaces were very "cello friendly." The mics used for the 3 programs were DPA 4006, Sennheiser MKH40, and some cheap Audio Technica mics. The DPA made me pleasantly surprised that the recital went that well (although the mics were placed way too high and were picking up too much of the room). The Sennheiser and Audio Technica made me question whether I need a new cello, new strings, or a new career. I must say in defense of the Sennheiser, I've heard it sound brilliantly on piano recordings.
Since that realization, I started moving back to my old, more affordable setup. After several years of experimentation with strings, tailpieces, and other gadgets, I am settled back on my trusty Spirocore tungsten C and G, and Jargar Classic D and A combo, and a light composite tailpiece. I am settled in knowing that my strings will sound great to me, regardless of the brand, when I hear my cello through my favorite mics with an able audio technician.