I think people have different opinions of the jacket because of the difference in expectations. Some expect the jacket to be 100% waterproof... for long periods of time. I don't think you can find jackets out there like that. Nothing's 100% waterproof AND has good breathability. Not the $100 or the $500 jacket. There's always that compromise. If you want 100% waterproof, get a $10 yellow raincoat. Also expect to be wet from your sweat.
Now for my experience, I only own two shell jackets: the Marmot Precip and the Acr'teryx Alpha SV. Both have worked well in short periods of heavy rain and extended periods of drizzling. The Precip I've used extensively in the Sierra for the three season. I've been more and more considering using it in the winter because it is light and you don't get rained on in the winter. The SV is a bombshelter designed for extreme use in varying conditions. I've used it in some of the major mountain ranges in the world inlcuding Alaska, Cascade and the Caucasus in bad weather.
I think you were asking about buying a tent before, just like that piece of equipment, consider what you are going to use it for. I think an I-Tent in Socal is still overkill.