The 650 line itself is durable (I can't vouch for tensile strength) and does feel somewhat softer and more supple than 550. Color was very close to the Paracord Planet photo (with my fairly high end monitor (IPS with pretty accurate color)). The pattern is very nice to my eye both in parallel strands (as in the Web photo) and as a single strand.
Shipping was quick (to Massachusetts).
Customer service is stellar. Very helpful, knowledgeable staff willing to make some effort to answer questions (I had a question about another color of paracord in my order that the customer service agent answered by going to the stockroom to check).
Very good experience all the way around.