Has your latest Linksys caused you grief or joy? I ask this question not because I have statistical evidence, but rather anecdotal. The last two Linksys devices I purchased have operated erratically. I advised a colleague to buy two (for bridging) recently and he could not get either to stop crashing even with the latest firmware. Checking forums, I'm seeing similar stories.
Linksys has moved from Linux to VxWorks (a proprietary operating system) for its latest routers and may be gradually transitioning its devices. The firmware these gateways are running are the first releases, and may be in the process of significant revision.
If you're seeing problems with a WRT54G v5 (check the underside) or other new Linksys equipment (check the version number), post a comment below. Please post, too, if your gateways are working perfectly fine. I'll post a summary if I get many posts.
Update: On June 8, 2006, Tim Higgins of Tom's Networking posted an interesting article comparing performance of the WRT54GL (essentially version 4 of the WRT54G, still running Linux) and the WRT54G v5. Higgins focused on performance, not reliability; I'm hoping he provides a case study of a stock unit's reliability, too.