Pros: price, colors, and sizing
Cons: velcro wears out, fabric gets pilly
The thirsties duo wrap was my initially sister's favorite cloth diaper system. She bought some and used them for a week, then raved and raved about these covers, so when I started my cloth diaper stash with my first baby, I bought a combination of these and other wraps. I never regretted having multiple types, especially since as time wore on, these wraps wore out.
For a wrap that's going to last essentially from newborn (8lbs exactly) to about a paper size 3, these are very reasonably priced. And of course, being Thirsties, they have some adorable color choices! The sizing system is the biggest plus of this brand.
Unfortunately, everything else wears out quickly, from the velcro to the fabric mine almost dissolved in the washer. My sister has had the same problem with hers, and soon we were both figuring out how to replace the velcro and spray the PUL back to life. Not ideal.
If you are planning on only having one baby, and cloth diapering only part time, go for it. Otherwise find a different system, every other Thirsties product (AIOs, pockets, etc) that I have tried works great.