The Kitty Tree's with ledges & cradles are definitely worth having when there are Yorkies around.
Now...my Yorkies, especially Abby take great delight in joining Tallulah
while she's making her way up to the highest cradle. They usually only make it to the lowest cradle due to Tallulah giving them that look of, "one more perch and I can't guarantee you're not gonna meet my sharp paws!"
I'll have to post a pic later of Abby actually sleeping on the lowest cradle...she might be part kitty!