Well, I can relate. I just went through the same purchase decision. I bought the G3 D850 in July for around $300. It was the max amount I could afford. I came from a Moto G, that although was a great phone, I wanted a better screen and camera.
I have had numerous LG phones in the past and I know their hardware is top notch. I never have cared for their software, but I thought I could live with it. The phone has rarely ever got hot, the photo's have been fantastic, it was able to handle my daily app usage.
Over the past few months, the LG overlay on Android 5.0.1 with the G3 has really gotten under my skin. It is messy and really hurts my productivity. Then the HTC A9 came out, Nexus 5X. I found myself really wanting to change phones. Then the OnePlus X hit at $250 and I thought, why am I struggling with this G3, that is such a good deal and nearly stock Android.
This past weekend, I decided that I was most likely going to sell my G3 and get something else. The G3 hardware is great! So why not at least try to Root and add a custom rom to it. As it turns out, my version with the 21r update is very difficult to do. It took a lot of hard work, but I finally got it done. I put CM12.1 on it (5.1.1) by Sunday. It flat out fly's now! Yesterday and today, I have been testing everything and adding my apps back on. I haven't found a single bug.
Bottom line, the G3 is now exactly the phone I wanted all along. I can't believe how slow the stock ROM was. No more stutters, lag, and many new features. Battery life is about the same. No heat issues (except when I was downloading all the apps). It is blistering fast. I highly recommend it if you think that you have the patience to buy a used one, root and ROM it. You can buy them here in the US used in near perfect condition for under $200.
Otherwise, I just can't recommend the G3. The Android Overlay they have really drags the performance of the phone down. It is a solid phone otherwise.