Series 3 vs 5 vs 7

The reason was that I wanted to know how big the difference is shaving results.
My conclusion: forget the moving heads / joints / scissors / blade that's all worthless. The biggest difference, and you can tell a little, is the engine performance. More, it is in my opinion not.
The areas of the face where the hair grows evenly are well shaved and thoroughly smooth by all three razors. Not as smooth as a wet shave against the grain but more thoroughly than a wet shave with the direction of beard growth.
The places on the neck, where the beard grows partly crisscross can not cope satisfactorily and the Series 7 for 230.00.
Initially, also, the upper lips problematic, but if you have only figured out how you have to hold the razor, and this area is satisfactorily smooth.
The reason I have the dry shaver initially tried was that I had a razor bumps / rash get in the face, especially around the mouth, from the wet shave, which is worse at / after each shave. This problem I have hardly at the dry shaving. So if you have something like that with issues, which I can only advise to test any of the above models.
On the neck I'm getting as I said not a good result with the dry shaver, there I shave wet. Strangely, I have the neck fewer problems with skin irritation after shaving the older I get. Who but the neck has problems with the wet shave, needs the above models do not look at it - unless the hairs are really evenly in one direction. Then even this beard could be overcome.

Criticism on the individual models:

The Series 390cc was my first model. He has the weakest engine, but by a very skin-friendly model. It provides virtually no shave in my neck area. However myself shaving convinced the face. Otherwise I would not have bought the other two models. If you go over the same spot a few times from different angles, the face is sufficiently smooth.

The Series was my second 550cc model. The engine is already more powerful, easier to handle and the shaving head up slightly "thinner" - which facilitates shaving in the upper lip area. The shaving of the face is a barely perceptible trace more thoroughly, but runs noticeably faster due to the more powerful engine, you do not so often go through the same points about it again. As a result, the shaving but also feels at not quite as comfortable as the 3 Series.

The Series 795cc was my third and so far last model. The engine is again something more powerful, the high-quality materials used - relatively much metal. In addition, the motor in the rotational speed is electronically adjustable. At the highest engine performance of this shaver has a 3-day beard climbed faster than the other models, and if you put the engine power to the lowest level he is as gentle as in shaving the Series 3, but with a better result. In the neck area, this model could be felt the best, but as mentioned above, is not always satisfactory. Unfortunately, this model is very difficult and again slightly larger than the Series 5, making it unwieldy.

Conclusion:
As low beginner to try I can confidently recommend 3 Series continues. But as I said, bring a lot of patience and not expect too much.
In value for money in my opinion the best of the Series 5 is not as much fuss as the 7 Series, committed in the face practically equivalent result, and cheaper by about 100.00. This model can I recommend it to anyone who are 40-50 charge for 3 and not the world. It achieved a better shave then also with the 7 Series not.
The luxury model Series 7 combines many good properties of 3 and 5, however, is a bit clumsy. In addition, just too expensive. Now that I have him, I use him at home, but on the go I prefer the Series 5 with. Whether any of the bells and whistles is the 230.00 value.