Lowering with stock 17s

[C300Sport]

I visited the local high end tire place today to ask about lowering, and +1 or +2 tire/wheel setups. I think I would be happy keeping the stock wheels for now and maybe just going +1 later on. The guy acted like it would be a really bad idea...like somehow if I didn't do suspension and wheels, things wouldn't set up right. Anyhow, he couldn't seem to produce any sound reasons for this and I kinda got the feeling he was full of $H!T and just wanted to make a bigger sale.
I understand the whole looks issue, and how the shorter sidewall effects ride and handling, but does lowering with the stock 17s have any dynamic drawbacks?

[Derspeed]

Your tire guy is full of . He wants you to spend your money at his shop. If you want optimal handling, sometimes bigger wheels are not the best option. Yes, you want a shorter sidewall, but not too short. You also don't want more weight. The folks that put 19" and 20" wheels on their cars are doing so to the detriment of performance and handling.

A few things from a few of my experiences:

Handling - 17" wheels will handle fine. My Passat is lowered on Bilsteins and H&R springs. With 18" wheels it handled great. My girlfriend has it now and did not want the wheels when she took owneship, so I installed the OE 15" wheels with good tires. It still handles great and seems a bit more nimble and there is less unsprung weight with the 15" wheels. I had a Saab, with OE 16" wheels with B&Gs and Konis and it handled great. I have done the same on quite a few cars and know people who have as well.

Appearance - the 17" rear wheels may look sucked in once your car is lowered, but you can add wheel spacers. I bought the 18" AMG option wheel because there would be no comparable aftermarket wheel and tire combo that looks so good for a $1,000. I am adding 10mm spacers so they will look even better.

The bottom line is if you like the wheels, keep them. They will be fine with a performance (lowered) suspension.