I'm sorry, but "preserve read/write cycle of SSD"? Are you kidding me?
HDD didn't have this issue... SSD certainly doesn't. If I'm correct, I can write 10GB per day and use it for 50 years. Since I don't plan to use my Air for that long, I'm sure reading-writing even 50GB will pose no issues.
If you're going to drop $1500 on a laptop, best not be conservative about usage.
I see too many people concerned about battery life... and now SSD cycle life?
USE IT TO THE MAX! You paid good money for it. Use it till you fall asleep faster than your MAC!
On-topic, I use a dedicated tracker and disable DHT, peer exchange, and local peer discovery (not that it is supported by the tracker anyways). I can limit how many people I want to share with at a time. I OCCASIONALLY use an open-tracker, and it's just too 'open'. like 10 trackers you're sharing over, especially if you enabled port-mapping (I think it is smarter to manually forward a port).
I have consistently downloaded at full speed @3.7mbps across my pc desktop, pc noteebook, and now my Air... no matter if with only 10 seeders for a large file. I don't think there are will be any issues. I'm still just on a wireless n 300 router (DLink).
Go Private!
But of course, I only download LEGALLY SHARED FILES! NSA GO AWAY! I IZ NO PIRATES!