New iMovie slow and crashing

Why Apple, why?!! It's my first time using the new iMovie tonight, and I thought I'd be done editing my 45 minute video about three hours ago. Instead, I'm only about 10 minutes into the content, as I've been dealing with lagging, spinning color wheels, sound distortion, sound disappearing completely (seriously, it disappeared from one small section, and then 10 seconds later, all the sound was gone), and then finally crashing. Fun!

After restarting, the video is also dragging and freezing at times. I tried to export just a minute of my edits to see what I was going to get. It told me it would be about three minutes to do the export. About 25 minutes later, the progress appeared to be only about 20% done.

So really, why introduce an upgrade if it's a pain to use. Yet this is becoming the norm with upgrades. I can't just use them. I have to relearn stuff and deal with crashing headaches and such. I loved Apple when I could just turn on a computer, or install new software and go. Those days are apparently gone.

Is it just me, or is there a simple solution that I'm just not seeing?