Torn between M7, M7 XL, or H2 for first Dynavap

I’m looking to stick to under $100 for this initial purchase, so I’m going torch only at first. I have an electric DHV but it’s not great, and was going to go with a desktop of some kind but decided something like a Dynavap is the route I’d rather go at the moment.

I’m torn between the M7, M7 XL, or H2. The reason I’m considering an H2 is because I’ll usually use this at home, and the glass is appealing. But if I ever do want to take it with me it’s fragile.

What are the benefits of the Helix tip vs the M tip? It’s only about a $15 difference between the XL and H2, so it’s hard to decide.