For the moment I am using Level 1 charging as my home's electrical service panel will not accommodate a Level 2 charger without an expensive upgrade.
There are rebates available in most states for level 2 installation as well as a federal tax credit, which comes and goes but is currently available again. So you might want to factor that into the cost equation if you haven't already.
That being said, even a high range PHEV like Clarity can usually stay fully charged with just level 1. There might be occasions when you don't have enough time to fully charge, but that will likely be somewhat rare depending on your driving schedule. When it does happen yes you do use some gasoline that you might not have used if you had level 2, but the cost of that slightly extra gas usage is usually minimal compared to the cost of installing level 2, even with rebates. You may want to drive the car for a while and see how often it happens that level 1 leaves you short before deciding on upgrading.
Level 2 does do better than level 1 for preconditioning, meaning running the heater or AC prior to leaving while you are still plugged in. With level 2 you can charge and precondition at the same time, whereas with level 1 you can only do one at a time. But for Southern California that probably won't be a big factor.
Not needing 240V is one of the selling points about PHEV that doesn't get mentioned often enough in my opinion. Longer range without having to charge is what everyone talks about, which is understandable. But it's also an advantage to be able to plug into a regular outlet and not have to install a 240V outlet. With an EV you pretty much have to install level 2 if you want to avoid having to charge somewhere, although that depends on the driver as well, even some EV owners do fine with level 1, but I think that is not as common.
One final point, if you haven't done so already find out what other outlets are on the same circuit that you are using to charge your Clarity. You should avoid using anything on the other outlets while charging. Small items like an LED desk lamp, etc. is probably okay, but certainly not a power tool or anything like. Don't go by just the description on the panel, those are too general, you need to test each outlet in your house to find out what circuit it is on. This only has to be done once and is valuable information that will come in handy for all types of situations. People are often surprised when they find out what other outlets are shared with the charging outlet.