I've got one on my carry on, but, how very, very sad FT tags are "relatively uncommon".

The OP is going nonstop to BUD, and I assume maybe returning the same way. On other carriers, you may encounter different rules outbound and return. For example, I take NW to AMS and catch a KLM Cityhopper with my carry on. Returning, when I go to check in at TXL for the local KLM back to AMS, they tell me my carryon is too big and I must check it. Which means I do not see it again(hopefully) until I get to customs back in the US. Euro airports and airlines have tighter size and number limits for carryon than the "carry on everything" attitude in the US. FRA has a sizer in front of the security entrance that most US sized carryons will not fit through. The 9 to 10 inch limits for depth allowed by US airlines WILL NOT fit. I think LH has a 8 inch limit--there are almost no rolling carry on bags sold in the US that are only 8 inches deep.

If you only carry one bag and hope to carry it a whole trip, just in case carry a folding tote or small backpack inside prepacked with your valuables, laptop, camera, medicine, things you need in cabin (NC headphones, inflating neck brace, etc.) so you can easily separate them from your clothes, without having to repack your bag on the floor of the check in lane, and without forgetting anything.

Even with only a carry on outbound, I carry a folding bag to use as my carry on for the return. You always return with more stuff (souvenirs, bottles of wine and beer, gifts) than you left with. Since you cannot carryon liquids anymore, I pack the liquids, gifts and goodies in my carry on for protection and check it. If it gets lost, the biggest loss is not the contents but the Eagle Creek bag itself.

Enjoy Europe.