Nick, I think you've already been there, done that, with respect to the R4, but I've been making a lot of matrixes lately -- eight in one weekend at the Fillmore Street Jazz Festival a few weeks back, and numerous others lately, maybe one a week for months -- and I seriously can't even imagine running without my R4. Man, I just LOVE IT. Now, I know about the HDD Slow thing, but honestly, I haven't missed a complete recording once, and I'm already on probably 20+ matrixes since I bought my R4. Also, sometimes I run 4 AUD mics and plug my JB3 into the SBD for 6 channels total (requires syncing later, but the flexibility of using one or both of the AUDs has paid off in spades a few times). The other thing is, the DVD battery I use lasts FOREVER even running 4 phantom with the LED on the entire time. If you have an R4 for this run of yours, and you brought your lappy, and you ran at 24/48 (not 96), you'd probably be able to have full redundancy/backup for the entire tour (not sure how many shows you are talking about). You could record via R4, and then right after the show drag a copy to the lappy -- bam, full backup within minutes of the show's end. Then leave the wavs on the recorder and lappy while you move onto the next city -- maybe you could keep copies of the entire tour on both machines? If not, you could always flac the originals and put them back on the R4 as flacs to free up more space and maintain full redundancy. Anyway, just some more R4 fluffing, heh..
(If you go lappy only, I'd still burn DVDs of the flacs as you go just in case your laptop frys, LOL! The other thing about laptops is dropouts. If that lappy isn't tuned very well, has lots of crap on it, extra processes running, and a fragmented HD, recording 4 channels at high bit rates could easily run into problems.)