It's all about the battery
I have owned and used Makita, matabo,milwakee and other 'famous' brands around building sites. All were cactus with in 18 months to 2 years and always because the batteries were cooked. To replace them (the batts) costs almost but not quite the ssame as a new tool with new batteries, so you guessed it new always! My last purchase was Panasonic 15.6 volt best tool I've owned, but alas 2.5 years later and batts are cooked. The problem now is that Panasonic is made in china and not quite as good as the 'older' models. Panasonic have(stand to be corrected) the highest amp hour of all the batteries and 'they ' say that the battery cells are made in Japan.
Now, Ryobi is pretty good really, I have the cordless saw and other bit and bobs that go with the 18v kit- very good value and charge up pretty quick, my opinion is that they are the best of the domestic range for the price, ok for light commercial use. 12v has the ability to work off car battery- very good option.
Mal