From C63s AMG to CTS-V?

Good morning, I am currently driving a C63s AMG and am looking for a successor from June. Through an acquaintance I got the “tip” to drive the CTS-V sample. At the beginning of the week I had a short-term test drive. I have to say the first impression was more positive than thought of both the quality and the overall impression of the brand. The vehicle had about 25,000 km mileage was from 2016 and the price was 50% of the new price. At the first driving impression the sound was completely different and you had to let it work for the first time. The AMG is louder and sounds more aggressive. The 650hp were not really impressive at the beginning of the highway, because my 63s incl. 102 fuel is really good in the fabric. After 30-40km and time and again full throttle the car went at once much better than the beginning and friends came up. I also think the “cheap” fuel was fueled and the wagon had everything that was possible at that time. Now my question and concerns: 1. Are there any weaknesses in the CTS-V models from the year 2015 onwards? 2. Unfortunately I didn’t look at the verb. Again and again you leave in forums of extremely high values this is correct? 3. What about the resale of Cadillac? 4. Are there still things to consider? Many greetings