Maybe not as poorly as things in rebel-occupied Donbass war zones, but about as bad as peacetime can get. They very badly underestimated the level of economic integration between Crimea and Ukraine / the rest of Europe (and by extension the economic and fiscal catastrophe that awaited a walled-off version of the peninsula). Crimea is in a crunch with no end yet in sight, and Russia is stuck with a very expensive bill its population and budget officials have already begun indicating they’re ready to skip out on.
Whether or not an overwhelming majority actually favored Russian annexation at the time — we don’t know how far off the hasty / sketchy referendum was from the truth — it’s pretty clear now that many voters would have at least reconsidered their pro-Russian instincts had they had better access to a realistic assessment of their prospects … or, at the very least, the benefit of hindsight from today.
Nostalgic Soviet pensioners and Russian-friendly organized crime thugs were never really a good foundation for the future, it turns out.