Personally, I'm not much aware of the cons, and if I may as collector, what I appreciate most is a complete database like
https://status.denarium.comNot just addresses, but also photos, how many of each release were made (can't believe how often this simple info is extremely hard to find, I'm looking at you Polymerbit!!!), everything...
And of course, if all the info is also available for download as .xls, even better.
Just my 2 sats.