Wow, I had one of these in each of my tanks for a couple months and as it got cooler outside I noticed neither would heat the tank properly so I pulled them and returned them. I used to be a big fan of Marineland, at least with the Emp. 400, but ever since the redesign I have been disappointed there too. Marineland is severely lacking quality control - not just with the heaters. I spent two months in emailing to resolve filter issues, and although the customer care was nice, it took 5 shipments of products to fix it.
edit- notice the filter I have now - not the Emp. 400 (horrible noisy grinding impeller from new, never could fix it)