Pubmed has needed an upgrade for at least 15 years. The fact you could search for the exact article title in the old version and never find it says a lot.
"The fact you could search for the exact article title in the old version and never find it says a lot."
This implies the need for server-level improvements, not changes to the user interface.
For that specific example, they needed both. You could craft a custom query to accomplish that every time in the old version, but you really needed to know what you were doing. Now that they changed some defaults in the UI and made search improvements on the back end, I haven't seen that specific problem since.