As expected, it was a long bus ride, but not too bad all things considered. While not as plush as their South American equivalents, there was enough space to lie down (as long as you're not too much taller than I am). Judging by the amount of time we seemed to be going up and down I suspect we missed some reasonably scenic country. We also stopped for around three hours between 2 and 5am (which meant the best sleeping opportunity of the trip), perhaps because road improvements on the Chinese side meant that pressing on would mean reaching the border before it opened (why they haven't simply shifted the departure time later is a bit of a mystery).
As is often the case, border arrangements were a bit confusing - we knew we had to get off the bus with our gear but weren't sure whether we got back on it after the Chinese exit point or had to walk up to the Lao entry point (we did the latter, and were pleasantly surprised that the distance was only a few hundred metres and not the 2km I'd read somewhere). Got through in the end, but probably took about 2 hours for the whole process (mostly because the bus was stuck in a truck traffic jam - it's the major trade route from China to Laos and Thailand).
The motorway goes to within a couple of kilometres of the border but it was immediately obvious that we'd crossed the border, as the road became a wide strip of dirt within a few hundred metres of the border post. (Other very large expanses of dirt in the vicinity, along with various buildings under construction, suggest that this will be a very different place soon). It was only like that for a few kilometres, but then the first 200km were relentlessly hilly and winding - reminded me a bit of some of the country out the back of the Gold Coast/Byron Bay (maybe not this year) - and we weren't averaging much over 40 km/h despite some occasionally creative overtaking. There's a drought here too, although you needed to look closely for signs of it because tropical areas will look fairly green at the end of the wet season, even a lousy one.
Made it into Luang Prabang only 90 minutes late, not bad by local standards (although I then added to that by doing some needless wandering trying to find my hotel). Haven't explored much yet but have heard very good things about the place from everyone who's been before. It's definitely much more on the Western tourist track than anywhere I went in China, and English is much more widely spoken than I expected, which makes organising logistics a little less challenging.
In two or three years time it will be perhaps six hours from Kunming on the train (the construction site was frequently visible), and Laos will probably become a very different place - the ultimate plan is to connect southeast Asia through to the Chinese rail network all the way to Singapore (although Malaysia has put their part of the project on hold after a change of government), which will put Laos squarely in the middle of a major trade route.