Big question... Five out of nine meetings I plan to attend this season will be held on carpet/astroturf, the other four on dirt. If I can spare the money at any point this year, I'll probably get the one-piece chassis as I think it will be an improvement. However, I don't know if it is really worth 90 euros with so many other items on my to-buy list...
Update on the RDRP RB6 servo mounts: They don't fit in the aluminum chassis with the BLS-451 as they push the servo slightly more forward than the AE mounts. I took some spare SC10 FT servo mounts, which work perfectly with the above servo, but have imperial threads...