This bike route is in a gorgeous area of Europe and VERY POPULAR, even during Season B. During high season, the paths around Lake Constance must be like L.A. during rush hour traffic! The pathways are a mixture and dedicated for bicyclists, shared with pedestrians, shared with slow moving traffic and through busy towns and quiet villages. It's mostly paved and the scenery is generally good to great. You pass through some limited commercial/industrial areas. Be alert for packs of fast paced road bikers and keep to the right, thus allowing them to retain high speeds as they are training for imaginary slots in the Tour de France. Some e-bikers are in fast mode as well.
If traveling by train in Germany to/from Konstanz, the DB Navigator smartphone application is good. The initial/last accommodation, Hotel Halm, is located perfectly across the street from the bahnhof in Konstanz. You are given a local transit pass (that you've paid for indirectly), which allows you to hop on bus #6 at the bahnhof and puts you within about two blocks of the bike shop, where you will gather your rigs. Staff are great at the bike shop. Riding from the shop back to the hotel is easy and mostly on a bike path. Taking a taxi to the bike shop is spendy despite the short distance.
The bikes are heavy, entirely suitable and well maintained. They have a much higher center of gravity than typical bikes and are like a supertanker as to maneuvering in tight quarters. Adjust your riding style, mounting/dismounting techniques accordingly.
The mapping is inadequate. Refresh your vocabulary in advance. We loaded an inexpensive Airalo e-sim good for the region, is inexpensive (3 GB data, $13) and valuable. There were some cell phone dead zones, however. Almost all locals were more than helpful in redirecting us to the proper pathways. Adopt the concept of when first lost, immediately ask for help. Of note: departing Konstanz and staying on the bike route was a PITA. The same for transiting Radolzell.
The hotels were fine and served good to excellent breakfasts. Also provided is secure storage for bikes each night. How all bikes are stored during high season must require significant imagination by hotel staff. Two hotels were less than ideal as to locations, including Parkhotel St. Leonhard, which is on the edge of town and high on a bluff. The other is Hotel Restaurant Seegarten in Arbon, and located well away from the town and restaurants.
Staff at Bike Tours are superior...thanks for helping book this trip! Tip: membership in Adventure Cycling gains you a discount.