The reasons to cruise at between 5,000 and 7,000 feet are many. The air gets thinner with altitude, which means less drag, which means your plane goes faster burning the same amount of fuel. But, as you keep increasing altitude, the air gets so thin that your engine can no longer make full power and it keeps declining in power as you climb higher. So, the "sweet spot" for performance (speed vs fuel burn) is about 5-7,000 feet.
Your passengers will start to get a bit sketchy as you climb higher, say to 8,000 ft or so. Pilots are used to changing altitudes, passengers not so much.
You might also find local weather causing you to select altitude. If you have puffy cumulus clouds, flying below the bases will be very bumpy and not comfortable. Around here those bases are often at 3,500-4,500 ft. Get above them at 7,000 ft and it is smooth sailing.
The biggest reason for new pilot dropout/washout is interruptions to the schedule. Either you get busy, or your instructor lands a job with the airline and disappears on you, or whatever. I did traditional pilot training and schedule for my private certificate. 6 weeks and 35 flight hours later I had my pilot license. (Yes, 35 hours.) I did the accelerated course for my instrument training. Total immersion for about 10 days. If you devote yourself as a good student you can do well with either of these routes.
Another fun little airplane that is not as capable but might be interesting to look at is the Cessna Hawk XP. It is a 172 with a six cylinder engine, making 180hp (factory) that can be upgraded to 210hp using an Isham conversion. 210 ponies in a 172 delivers pretty good performance, although it is the smaller cabin with less comfort than a 182. I owned one of those for a while. They are vintage 1977/1978. I think the 1977 models were 12V and the 1978 and up were 24V.