I haven’t had enough time to really get some wear and tear testing in,but it looks like as of today, the latest Ubuntu Ibex Alpha release runs almost flawlessly on the Toshiba Tecra A4 (PTA40E). Wireless and the Wired NIC work without any kernel boot options, and performance is much improved without noapic.
There are just a few minor annoyances like what appears to be a remaining quirk with the ipw2200 driver restarting in some rare cases, but it looks a lot less frequent. Dimming on battery disconnect and function keys are still broken, but neither of these is a big deal.
In any case, it’s definitely usable now, and Ibex is looking pretty sharp.