"Should I be worried"? Simple answer - yes.

Keep in mind that Grohe is German made, and, like all other German made products, are over engineered.

Speaking firsthand, my sister-in-law had a Grohe kitchen faucet (Original cost $500) and the internal cartridge caused external casing to crack. Cost of repair part $250.

Almost $1,000 dollars invested in something so simple.

I think I would stick with Moen or the like.

We have 3 Grohe faucets in our home, one is 15 yrs old. I did all the remodeling, and installed the faucets / shower mixer. We are quite pleased with the performance of the products. They have a complete service center (I think in Illinois) and you can get any part for free - as long as you are the original owner, and have the receipt.

IMO, they are not over engineered, but rather thoughtfully designed. It's my opinion that many 'plumbers' would rather not read, install the units improperly, and then blame the product.

For instance, the shower mixer we purchased can be completely serviced from the front. It has integrated shut off valves, so you don't need to install any in the wall. It also came with installation templates for tiling. The downside is that you should read and understand the 4 - 5 pages of documentation that comes with the valve.

I downloaded the instructions. There are a few pages. ;)