This is quite true (performance may vary) as this will change from game to game. Some will load, others will crash when playing or some elements will not be visible when playing. There was one game that did load but the text didn't display which was very problematic since it was a very text-heavy game. When trying a previous build of Vita3k, the text showed up OK.
The development is still ongoing but like many emulation things, it is a matter of trial and error and persistence.