The store is relatively small, staff attitude is average, they do not proactively answer questions, and there are language barriers.

It's fine.

If you're landing at Terminal 2 of Frankfurt Airport, I highly recommend this rental company. It's extremely convenient; the office is the first one you see when exiting, and it's very close to the parking lot, making both pickup and drop-off very easy. The front desk and parking staff provide typical German service—very warm and friendly.

The service was quite satisfactory. It's best to pick up the car on time, otherwise, there may not be a suitable vehicle available if you arrive early.