Just looked at a Cabelas catalog - it shows that the Shimano Spheros (2004 model) does have the anti-rust bearings!
Keep in mind the Stradic is more $ also because it does come with an extra aluminum spool. It has a folding handle, and etc.
Either way you can't go wrong IMHO.
I do comparable diameter mono (three layers) and all the rest is braid. Its safest to have too much line than not enough.
If you have 300 yds on there and you get spooled then at least you have a hell of a story to tell afterwards.....LOL. On average you probably never need 150 yds.
Some people love one brand over another and if one brand was THAT much better than the others then everyone would be using that one brand. Its like a car - do we all drive the same make & model?! :P
FYI - braids have varying breaking strengths and diameters than they REALLY are. Thats a whole other topic.