I have to disagree with your statement on Gilligs. While I do agree that their buses have gotten better, they are still pretty crappy buses. When I ride those in Buffalo, even their newer 2010 buses rattle like crazy.
Additionally, when it comes to the LFS first gen, again in Buffalo, these buses run in extremely harsh conditions, yet they still ride as smooth as the 4th gens that Buffalo just bought. It's amazing because how well the buses have held up for so many years. The only thing that I saw need repair on those buses were the doors, but pretty much everything else was in good condition. In fact, Buffalo started retiring their newer Gilligs over the 2000's LFS because they hold up better.
On a side note now that I'm on break and back in the city, I've gotten a couple chances to ride the Xcelsior from CS. HOLLY CRAP like what happened to these buses? Their ride quality is almost as bad as the Gilligs I've ridden in Buffalo. My worse ride was yesterday night when I took the Q44 from the Bronx, I always remember the ride being bumpy with the LFSA's but this was the first time I came from the Bronx with an XD60 and it was absolutely horrible. At this point, I'm not sure if it was the buses or the road that got worse, but I do remember when the XD60's were new they even smoother than the XD40's.