Hi guys, 
Thank you for the generous amounts of commentary and feedback. I appreciate the thoughtful, non-smarmy replies.  
Some of the concerns you guys have intuitively figured out. 
1) On reliability, how long can be expected before major repairs? (e.g. ring-job, overhaul, major teardown?) 
2) Any known trouble spots besides the Rear Main Seal?  Any way to improve the reliability of RMS besides to keep an eye on it? 
3) I would likely be keeping the Boxster S in stock trim.  Any reliability mods needed? I know to avoid oiled foam air cleaners, and to make sure to change the 9+ qts of oil regularly.  
4) What is the 'porous block issue'? 
Any other thoughts?  
To answer questions posed here: 
* I have no qualms about buying from my 'bro.  He and I are good friends, and both of us are fanatical about keeping our cars maintained.  He is finicker than I am, and won't drive his car in the rain or bad weather.  I am happy to make a vehicle a daily driver. 
* I'm sure we'll be agreeable on price - that's not an issue. 
* Yes, I have driven it once - on a summer day, with the top down. Was expecting to be underwhelmed after driving my RX7, and was surprised that it was fast, super-sharp handling, etc.  A terrific ride. 
* Totally subjective here, but I think the RX7 is a sleeker design. My reasons for considering a swap is because of reliability and fun-factor.  Some have warned me that the costs of maintaining a Porsche Boxster would far-exceed anything I have seen with the RX7.  For example, a complete engine rebuild and swap at a reputable mechanic would be $4-5K, labor included, ready-to-drive.  I would likely need to do this at around 100-120K miles, from what I can gather. How's it for the Boxster S? 
Sincerely, 
Rob 
