Had an 12" black and decker chainsaw for 5 years. Never a problem but cutting anything thicker than 5" with it was had work. The auto Oiler didn't work more recently and i got through several chains. Finally, the tensioner which was always a pain finally packed in the middle of a job. So I bought one of these. IT'S ABSOLUTELY BRILLIANT. Took me 15 mins to read the manual and set up. The chain tensioner is really easy to use and the automatic oiler works great ( in fact it gets through oil quickly, so buy a big container full, it'll work out cheaper in the end). But once cutting I was amazed. I spent 6 hours cutting logs for firewood up to 14" thick and it's like a hot knife through butter, no matter how thick or hard the wood the motor doesn't struggle at all. It's not too heavy and comes with a usefully long lead - 10m (the bosch I looked at only had a 4 m lead) and this is great if you have to go up a ladder. You don't want an extension lead up there with you. At no point did it labour, get hot, no smoke from the wood. I got tired before the machine did. Will be going out tomorrow for another long session with it. If you are considering an electric chain saw get one of these. They do a 2000W model as well. But I didn't have any power problems with this one and its more expensive.