There are definitely cases on both ends of the spectrum. Some people in this forum have shared NIGHTMARES (encountered through no fault of their own) that I can't even imagine facing.
Our story was an easy-breezy success, in hindsight. Inland applicant, landed in just under a year despite some rather egregious errors and oversights on our part (I'm counting it as under a year from when our *complete* app was received, not from when CIC first received just the sponsor's portion a few months earlier; thanks, Québec, for confusing the hell out of us!). No real problems at all. However...
While living through it, it felt very different. We were so lost when we started the app, and despite applying inland, because of my husband's job, we were separated right away for almost 5 months (he's bilingual, I'm NOT, and I really struggled in our very French area). I was so scared I'd screwed things up (and I had, but was able to fix them, thanks to what I learned here). And then there was the inconsistency and not knowing why two similar apps were treated so differently. Some people who applied just before us were receiving AIP back in March and April. Then came the Silent Summer of '13. It seemed almost as though CIC had packed it's bags and closed up shop, so little good news trickled in from other applicants. I'd expected to wait around 6 months to get AIP. Then came month 7. Then month 8. Then my dear, sweet, IMPATIENT father-in-law booked a family trip for March 2014, a trip I couldn't let myself think about, because with each passing week, I grew more and more sure I wouldn't be able to travel by then. Then came month 9. Then came month 10. It had started to feel like a dream, one of those dreams where you run but never gain any ground. Some days, it truly felt like I would be waiting forever.
Then we got really lucky. After a call from CIC requesting I fax another copy of my passport (which had been sent; that's one mistake I *didn't* make), I received AIP and DM in the same glorious, unforgettable day. Suddenly, I KNEW I could go to Europe with my belles-familles, I KNEW I could start thinking about visiting my family, and about teaching my only nephew that he has an Aunt Megan. I KNEW it was almost over.
Again, in hindsight, our process was easy, timely, affordable, and successful. But I did my share of whining and fretting on this forum as the quiet summer months dragged on. And we didn't face nearly the level of challenges that some on here face. I'm American, so I'm visa-exempt. We have no children, no complications, and I was able to be in Canada with my husband (well, when he's home, we spent fully half of our first year here apart). We're lucky that his job supports us relatively comfortably, so we didn't feel the massive financial stress that some here are under. And it only cost us the standard fees ($1306, since we're in Québec). But despite our "easy road," it was a hugely stressful process. I'm SOOOOO glad it's over.