My wife says the stock seat is the best she's ever sat on. We've done multiple 350 mile days without a problem. We still have stock seat. I've done 800 mile days on worse seats. The multi seat is very good for me, I know I could do a 1k easy on it.
My 600 mile service was much less than $300. Currently have 5k miles on the bike. Only real problem has been the fuel gauge, replaced under warranty.
A helmet will fit in the side bags with the large covers. The top box is awesome.
If electronic suspension is not your cup of tea, price out a base or ABS model with the additions you want (side bags/ top case, center stand). The multi then becomes even more $ competative to other models. The base model forks are very good.