...for assistance with some shifting issues. The mechanic asked if I'd like the full tune-up, which includes bearings adjustment. I'm wondering, wrt to sealed bearings, just what there is to adjust. The hubs and bb seem to be spinning fine so I declined. Is it a good idea to open up these components every so often for an "adjustment" or re-lube or should you just leave well enough alone if it don't seem broke?

in your specific case - Depends on which bills will be short that month!

I don't know what type of wheels you have, but my Ksyrium's bearings are adjustable from the outside of the hub with a special tool, other wheels probably have a similar setup. Like your headset you want just the right amount of tension so that there is no play, but the bearings still move freely. As you rack up the miles the wheels will need the bearing tension adjusted to compensate for wear. The mechanic will put the wheel in the truing stand to check/adjust the bearings. Generally while they are at it they will also check the wheel for trueness. The point is once a year it is a good idea to get the full tune up, it will save you time and money in the long run.

As stated it's a good idea to remove the crank arms and check the bottom bracket annually to see whether it's in need of replacement. Regarding the hubs, most, even those with cartridge bearings, can be adjusted, and thus they should be checked on a regular basis also. If you're capable and have the tools, do the inspection and replacement and/or adjustment yourself. If not, the mechanic gave you good advice so let he/she do it. Good luck.

Not sure how many LBS's by me would put Ksryuims in the truing stand and check them, check the wheel bearings, ect.... Think they would do a fast tune up and skip the sealed bearings that didn't have any play in them.

There is a lot less to do, but as was suggested, it is a good idea to check the torque in the bottom bracket, take the pedals off, move the seat post. Just to keep them from seizing. All best done yourself if you know how.

According to a few things I have read, it's also a good idea to clean and lube the freehubs once a year if you have Ksryuims. Doubt many shops do that around here, learned about that through the internet.

Not sure how many LBS's by me would put Ksryuims in the truing stand and check them, check the wheel bearings, ect.... Think they would do a fast tune up and skip the sealed bearings that didn't have any play in them..
I am very lucky, I have a great relationship with the guys in the shop. There is no way they would let my bike out of the shop without checking the wheels for true if I had them look at the bearing tension. An example of their work ethic, when they put a new chain on yesterday the mechanic did a quick once over on the bike and checked the brakes, derailleurs and tire pressure. No charge except the cost of the chain. As a result they get all my business.:D

The amazing thing is that compared to my first bike, there isn't as much to be done anymore. Not sure there is even a local shop that would build a wheel for you. They just don't do that stuff anymore.

On a road bike...brakes, shifting, and chains are really quick small things. Nothing like overhauling hubs, bottom brackets, and headsets that used to be done in the past.

Changing cables and adjusting the derailuers are within the grasp of the home mechanic. Swapping out my Ksyriums for race wheels a few times a year got adjusting the gears down to second nature. Once you get a system down (see the park web site) it's pretty easy.

New factory wheels are not really user friendly truing wise. Everything is gone disposable.If it wasn't for the XT hubs on my mountain bike I wouldn't even get to do that anymore Thank god for mountain bikes, so many things to break :-)

I have even volunteered to work on friends older bikes, just so i can play with the old tools. :-)

I would never get the "full" anything for service at a bike shop. You often end up paying for more than what you need. Ex: You just need a derailleur adjustment and brakes adjusted, but you don't need anything else done. So why pay for the extras you don't need? In cycling, the old adage, "if it ain't broke, don't fix it" really applies here.