All quote vendors experience delays caused by a variety of problems, network overloads, fast markets, router problems, server backlogs, buffer overruns, etc.
To close your eyes to that fact is not a good idea; or is it to rely on a single vendor.
Posting a market at an ECN or an electronic option market is not an accurate measure of overall quote speed or data integrity. Different systems have different algorithms for prioritizing orders, quotes, informational quotes vs quotes on a live order. The problem is not one for the human eye, quality of data can only be determined by measuring a huge data stream against another, or multiplies in different market conditions, market days, etc.
In summary there is no best, except for the best at the current time ...
To close your eyes to that fact is not a good idea; or is it to rely on a single vendor.
Posting a market at an ECN or an electronic option market is not an accurate measure of overall quote speed or data integrity. Different systems have different algorithms for prioritizing orders, quotes, informational quotes vs quotes on a live order. The problem is not one for the human eye, quality of data can only be determined by measuring a huge data stream against another, or multiplies in different market conditions, market days, etc.
In summary there is no best, except for the best at the current time ...