Having flown both my observations are:
1. The 175 climbs out like the proverbial homesick angel compared to the 172. I believe it has a different wing section.
2. It also has great short field landing characteristics which I think are a little better than the 172
3. In terms of the wobbly prop, gearing etc, I'd suggest you talk to you instructor about the various settings. I didn't think the skylark was much different to a 182 for engine management. If you have a jpi EDM 700 or 830 device installed, then will allow you to really get the best out of the engine.
4. As BPW says other characteristics are v similar, though I think the 175 goes a little bit faster at 130mph cruise for about 34 lph as I recall.