It's unlike sea cruising in that there was almost always something interesting for us to see as we sailed up the Rhine then down the Danube. The cabin was very comfortable - just enough room but with a glass wall & door on the river side to create a feeling of space. The balcony was an extravagance but very enjoyable - we often drank our coffee out there and watched the world pass by. (There is a coffee machine in the lounge that makes excellent coffee in one of six options.)
The crew were all friendly and the food very good - sometimes excellent (except occasionally a touch too salty for our taste - we're told that more rather than less salt is a characteristic of European cuisine). The only disappointment was the cheese platter - always the same poor three samples. The beer was good & the wine OK. During meals drinks were free. (Apparently from 2013 all beverages including bar service & mini bar will be included in the fare.) I was very pleased to find that no one wore, or was expected to wear dinner suits throughout the cruise - although "formal" dress was sometimes suggested it really meant neat casual.
I know there were two Canadian & two US couples aboard, but, the majority of the 170 passengers were Australian. Everyone was friendly and welcoming. The main dining room is free seating with tables for two up to eight usually. There's also the small Portobello restaurant which each passenger is invited to dine at once. It's just a few tables at the front of the lounge. We were disappointed in it, finding it did not to live up to its claim of higher standard fare.
The sight-seeing organisation was efficient & a number of choices were offered. We enjoyed most of ours, but, I don't ever again want to be part of a group following a flag-bearing guide. Excursions frequently set off at 7:30 or 8:00 - too early for my comfort but I think necessary to "beat the crowds" at popular attractions or to fit the sailing schedule. Several excursions involved bus rides of two or more hours. In this respect, I guess the cruise is similar to a land-based tour although usually, during such excursions, the boat continued sailing and we rejoined the boat further along the river so the long bus ride was mostly one way. Where the cruise couldn't be matched by a land-based tour was the passage down the Rhine Gorge & later the passage from Passau to Linz - both were unforgettably wonderful sights. (Of course, the most obvious advantage of cruising is only having to unpack once.)
There were also a number of special "events" - a tour, dinner & entertainment at Marksburg Castle, a "Village" event with eight options to choose from, & a Classical concert at Palais Liechtenstein in Vienna. All three were excellent. My highlight was visiting what was described as a "Piano Collection" in the Village event. When the bus arrived there and we told we'd be there for two hours I thought I'd soon be bored, but, oh no - Michael Gunther is a pianist who showed us eight or so of the 30 odd Harpsichords and Forte pianos he's collected, including one whose provenance strongly suggests it was played by Mozart. Michael also played them for us for more than an hour. How Scenic managed to find such a talented and generous fellow I don't know, but, I'll long remember his music and feel privileged to have heard it.
There was some on-board entertainment: a zither player, a glass blower, a beer tasting, a lecture on the European Union, a Bavarian brass group, a crew comedy show & Hungarian folk dancing. The quality varied but was mostly fun. However, it was spoiled because unless you grabbed a seat early it was difficult to see. Scenic are renovating their fleet so maybe they'll reduce the size of the lounge bar (which looked about twice as big as it needs to be) and make more room for passengers in the lounge. There was also a musician who travelled with us, but, I found his music too contemporary and loud for my taste.
While the excursion guides were almost always very good, we did have one that I wouldn't employ (an ex-pat rather than a local which in itself disappointed me). The biggest complaint we have of the guides is that Scenic provide personal headsets so that everyone can hear the guide. Unfortunately, most guides didn't wear their headset properly, instead hanging them round their necks so that when they turned their head (very often) their microphone didn't pick up what they were saying. (Scenic say that from 2013 they'll offer portable GPS devices loaded with sightseeing tours & commentary so that you can sight see at your own time. I think I'd choose this over joining "mother duck & duckling" guided groups.) The excursions & events were, of course, optional, so one could always stay aboard (we did that from Passau to Linz as we couldn't face the long bus rides to either Salzburg or Cesky Krumlov). I also took one morning off because the pace had tired me out.
My final criticism is the "private Butler" service provided on our deck. I'm a simple fellow and frankly don't have a clue what do do with a butler. Scenic suggest that they could bring us breakfast (we preferred to meet our new friends in the dining room), bring us drinks, clean our shoes, or provide a concierge service. Now such services are commonly provided by good hotels without "private butlers". Scenic are apparently going to extend the butler service to all cabins, but, I'd recommend that instead they dispense with the hi-faltutin' nonsense entirely and just provide prompt service on request (as all the staff already seem to do).
Despite the small criticisms, we can but recommend Scenic Tours Rhine/Danube cruise. Others may do it as well but I very much doubt that any could do it better. It was a real wrench to leave the Scenic Ruby in Budapest. We stayed there for an extra night and met some of our fellow passengers in our wanderings there and we all agreed - we resented that strangers were on "our" ship, in "our" cabins.