Uverse HSI self-install vs pro-install at different tiers

I am in the process of ordering Uverse internet only (no TV). When making my selections, I see that Max (12Mbps) has self install available while Max Plus (18Mbps) and higher require pro install. What are the hardware requirements or differences between the tiers? I read somewhere else on this forum that a user has a CAT5e cable running directly from the NID to the RG. Is that the only difference of self vs pro install? -- You can never waste time cuddling a puppy. That time comes back to you later in affection from the dog. My Snowdogs