A few comments:

First, answering your question, your plan to stay in hostels and hotels is significant: it lightens your load. I've toured both relying on camping (stealth and legitimate) and staying at B&B's and hotels. The former adds, at a minimum, a sleeping bag, and probably a tent to the load. For me, that meant relying on a full-sized frame. Staying at hotels, B&B's, and hostels means carrying less and my folder (a Swift) was ideal for the reason you mention: easier access to public transportation. (This doesn't mean you can't successfully tour on a folder if you're carrying a sleeping bag and a tent, but planning the load requires more ... planning.)

Second, depending on where you're touring, it's worth inquiring about the availability of rental bikes. This is far from universal but it's increasingly common. If your plans include flying commercially, the cost of a rental bike may be comparable to what's involved in bringing along your own bike as checked luggage. I can easily (and Swiftly) pack my Swift for air travel. This is less and less necessary.

Last, I like my Swift for travel because while the frame is proprietary, all the components are generic. If something breaks or requires service, most bike stores will have something that fills my need even if it's not precisely what I want. This isn't to steer you away from folders with proprietary components; just alerting you to one consequence of that choice.

Hope this helps.