I can not speak about "tinys" because Remy is my first Yorkie and I do not know any one who has a tiny. Remy is 9 months old and just over 6 lbs. He is likely full grown, may end up at 6.5 lbs.
I can tell you that I am glad he is a bit "bigger" because even at his size I think he is fragile. Given my experience with him thus far, I am not sure I could honestly handle the extra care a tiny would require. Tinys are adorable, I am just being honest about my experience, and my lifestyle
My only suggestion, regarding the "size decision" is to really reflect on your lifestyle and consider how it will "fit" with your new furbaby.
Remy goes to work with us every day and is
incredibly active. It is hard enough to keep an eye on him (jumping prevention, etc) however at his size I do not feel like I have to worry every second. My extra special attention is focused on when he starts climbing (couch arm or back) If he jumps off a couch cushion or an ottoman he is fine. I still try to limit it, but given his personality it is extremely difficult - he moves like lightning!