Borrowed the first one from a friend and only played it a couple of hours before I dropped it.
That had several reasons though I only remember them very foggy: 1. The story just didn't get rolling. First quests you did felt like doing some random quests in a MMORPG. In order to get X you need to help 3 NPCs, each want you to do a "kill 10 X" quest. Was a horrible start. I also remember that Drakensang had longer Texts, which were not interesting enough to keep my attention for their length (in difference to Avernum for example where the content and importance per sentence ratio was much higher). Last thing I remember negatively about the game was the time spent for running. After a little conversation you spent Minutes of running through the city again to get to the next snippet which then again sent you back running through the city. And with running I actually mean walking slowly without fast traveling.
River of Time basically improved all of it: The quests were more interesting, the texts were all voiced with extremely good voices* like the voice from Brad Pitt, Ben Afflek, Leonardo Di Caprio, Julia Roberts and I also remember the Spongebob voice on the market. One of the most memorable moments in the game I had right in the beginning when you try to listen to the other passengers mumbling and as soon as you got close to them they said like "pssst, the boy is coming over again" and started to talk about random crap like the weather. Combined with the creme de la creme of voices the staging of the game was awesome. Of course that is the German version. Can't speak about the english one. I guess that the high costs for the voices in the German version might then also be a reason why the money management for the game did not work out so well. They maybe should have spent more attention to the international version.
But back to the game: I mentioned the horrible traveling times in the first Drakensang, they fixed it in the second game. And while I don't remember much of funny moments in the First Game, River of Time had several of these. So you meet some philosophers in the Inn which were talking about hilarious stuff, and it also had a funny reference to the first Realms of Arkania game as you met a group preparing to follow Hetmann Tronde's call.
If you speak german and played Dragon Age, you might want to take a look at the comparison I wrote a while back on
myBuffed
After that I couldn't wait for the expansion: Philleassons Secret. And I can tell you that this was one of the most horrible expansions I played so far. Not just that I didn't like this egypt-like setting: The quests were also stupid and random, you were also sent back to random places for a couple of fights as if their goal was just to throw random content into the world. Out of the 6 hours of total playtime it brought, 4 were boring as hell (I can hardly remember the content but I wrote a little something about it back then):
1. Find 3 artifacts for 3 people and go into 3 caves for that, to just revisit all zones from the basic games. The caves are done within 5 minutes.
2. Fight for 6 artifacts in 6 rooms, where you encounter the same enemies over and over again together with a NPC which gives you the same sentence each time. After you did this you had to use these 6 artifacts in 6 different rooms. Pure boredom.
3. Thre were dialogue-quests like "if you want to join us, you have to make an oath on an element. Speak to my servants and chose one". You speak with the servants, chose one and get a reward. Completely without content and with totally dumb dialogues.
So to summarize it:
Drakensang wasn't exactly my taste, too many flaws. But it might be enjoyed by others who don't have problems with these.
Drakensang River of Time was an awesome game (in German at least, can't say anything about the translated versions) and almost on par with Dragon Age 1.
Phileassons Secret was a horrible experience and I would recommend to skip that. You might even skip it if you already own it because it might ruin your overall impression of the game.
EDIT: What I forgot to mention is that the normal Collectors Edition (not the persolanzied one) of River of Time also included the best coth map I have gotten so far. I framed it and put it on my wall (59cmx42cm):
*for non German people that's probably hard to understand but in Germany some voices like the voice of Bruce Willis (which is not in the game) are cult by themselves)