Hi I think it really depends on your experience, space and able to provide what each species needs, to know which species or age size you would prefer to own. Personally I love Burmese Browns but I do not have the facilites to accommodate its needs, so I just admire from afar. I have two hermans one is a juvenile 5 yrs old and the other an adult 25-30yrs, so I have both sizes, and each have their own needs and teach me, I love them both the same. Hope this has answered your question. Is this a pre question before you get a tortoise? Jane