Yes, and no. I liked the idea of the new area and quest, but other than that, everything is short like "here's a great quest! enjoying it? yes? Oh well we ran out of ideas-- here's the end!" It literally only took me a day (~13 hours) to complete the main questline, and that includes sidequests and gathering all of a special new armor set that is found at each corner of the island.
It's also glitchy as hell. I'm getting lots of freezing and CTDing even without playing the DLC (only have 'Dragonborn' quest started). I'm trying to get the Elder Scroll for the vanilla main questline and I can't make it through Blackreach without the game frikkin' crashing or freezing on me. And on the other character, I ran into plenty of glitches that made it impossible to continue forward without fixing something or reloading to a VERY long time ago (like the beginning of a certain temple because load screens to the outside would always freeze until I did the entire dungeon over).
Dragon riding is... forgettable.
A Dragon Ride gives you the same sort of experience IMO.
Here's a video detailing how it works in Dragonborn.
I felt like the DLC was somewhat difficult. Even on novice, some enemies were real PITAs for me with a level 65+ character(I think she's level 68 now at the end of the DLC?). It wasn't hard to navigate, and whenever I wasn't plagued by CTD or freezing, I enjoyed exploring.
My advice is to wait and watch the Skyrim Nexus for DB mods and wait for a Steam sale(unless you have plenty of spare cash laying around and won't miss 20 bucks). It's fun, yeah, but it's extremely short and not really worth the price tag with all the damn issues it has.