ive imported around 2000 images, and it didn't take much, also take into account i only have 8gb of ram, so it did pretty well and pretty fast. first it crashed a few times but because i had a 300mb gif and it tried to read it and crashed. i have around 5000 images more but ill import them in batches because those are relatively organized in folders so it'll be easier to add tags as i go than dump everything and figure out what do to with them later. so far i dont notice any lag with my collection, during import it may take a bit more if your collection is larger tho but if you also have more ram... it also has Redis as an option for caching, i havent used it tho