We lucked out - fantastic weather (only rained on once for about 10 mins), we had no water level issues, and although we had to swap ships half way through, due to a broken lock, Viking handled the entire swap seamlessly.
We have had great experiences on on several ocean cruises (not Viking) before this Grand European river cruise with Viking - OMG this is a whole different world. I can't list all the pluses: the smaller ship is so easy to get around and less people getting on/off in each port; you are able to get to know most of the staff; the ability to find a seat in the lounge or on the top deck when you wanted to; the free water in our room and when we left the ship each day; never being hounded to pay for photos that a ship's "professional photographer" would insist they take of you; the relaxed atmosphere; not having to get on a bus for every single shore excursion; the list goes on and on.
We traveled with my parents (in their mid-80s, we are in our late 50's) We stayed in a French Balcony room at the end of the ship. Loved being able to open the large sliding door to watch the world go by and enjoy the fresh air when we wanted to - but to be honest, with so much room in the lounge or the top deck, we didn't spend all that much time in the room (but again, we had post card perfect weather the entire trip) My parents had a balcony room on the 3rd level, and the extra room and the balcony to sit out on was perfect for them.
It is a very efficient use of space - it's tight, I won't lie - but we didn't spend all that much extra time in there anyway. And as long as you understand a French Balcony just means you have a large sliding glass door to open to enjoy the outdoors and the extra natural light with all the views from your room (and not an actual balcony to walk out on to) you will love it like we did.