Ok I listed the main cons already. Add that the apex seals in the RX-7 wear out much more quickly than their piston equivelent, which is the rings really. Not heard anything about the 8's YET.
For the pros, they generate lots of power for their displacement, love to rev and can rev highly. Very smooth power delivery but plenty of engines offer that.
It's different that's for sure but I don't think there's real place for rotary engines as anything other than a gimmick. If you want N/A high revving and high peak power there's V-TEC and it's mimickers (VVTi etc) but you can still retain good MPG and bullet-proof reliability.
The RX-8 is just lame and a big step down from the 7 imo and the 7 has too much competition to be a good choice in it's class. Also, has anyone noticed that the RX-8 has quite a high insurance grouping considering how fast it ISN'T?