I love CroisiEurope river cruises, but they are not to everyone's taste. The main language on board is French. You'll find there are few English speaking guests. Excursions aren't included in the price (except for cruises sold in the US where the prices are higher to take that into account). Cabins are small and the shower room is tiny. If you want to be cocooned in your own little piece of England (or America) and don't speak any other languages, you need a different cruise line.
We went on Victor Hugo for a trans-Europe cruise from Strasbourg to Budapest. This is really a repositioning trip to get the ship to Budapest for the summer season, but it's a great way to visit 5 countries.
We're not great fans of organised excursions. We prefer to disembark on our own, see any major attractions on the way and have coffee with the locals. That makes CroisiEurope cheap. One point to note is that with a repositioning trip, the ship needs to get through the Main Danube canal as quickly as possible, so some excursions are dropped off at one port and picked up further along, leaving no opportunity for others to disembark. That's not a problem if you enjoy sitting on deck watching the world go by. There are only so many pretty German towns you can take in on one trip!
A few tips along the way: Strasbourg is an interesting city. It's worth arriving the day before the cruise so you have time to explore it. Don't miss the Cathedral and the riverside district of Petit France. In Mainz, there's just time to walk into the old town, see the Gutenburg Bible in the museum, see the Cathedral and get back for lunch. (The organised tour doesn't go into either). In Esztergom, you can walk across the international bridge into Slovakia and tick off another country. There's still time to climb the hill and see the Basilica. In Budapest, the trams and buses take you anywhere you want to go. Buy a Budapest card and you can hop on and off at will. EU citizens over 65 travel free - just be ready to show your passport.
Meals onboard were excellent and standard drinks in the restaurant and at the bar are included. You can pay extra for premium brands, but the standard fare suited us. Of course, on a French ship you can't get a decent cup of tea. We took a supply of Millac Maid to avoid the UHT milk. You can buy fresh milk ashore, but there's no fridge in the cabin.
Our cabin was arranged with a double bed with one side against the wall. Bed covers were for two single beds so they soon finished up in a tangled heap. With the benefit of hindsight I'd recommend going for two singles.
The entertainment staff on this trip were French and worked very hard. The rest of the crew were nearly all Hungarian. Announcements were in French although they provided a translation for the 8 of us who spoke English. The bar staff seemed happier speaking French or German. Entertainment mostly took the form of games but the crew managed to put on a couple of shows.
Currency onboard is the Euro although the only things we actually had to pay for were a couple of postcards and our one excursion (a visit to a Hungarian folk evening in Budapest). All major cards are accepted. Tips are entirely voluntary. Towards the end of the cruise, you are given an envelope for tips and a questionnaire, but there's no pressure to return either.