Shimano will have an updated line up of tiagra's out within the next month, I think. They will have thicker anodizing, chromed sideplate screws, ratcheting drag lever, lower viscousity? grease for better freespool, and a new and improved handle.
All of the tiagra's are lighter in weight, except for the 50's and up.
I just hope the new anodizing doesn't make them the same color gold as the penn's.
We use both Penn and Shimano aboard our boat. I have mostly Penn SS and Slammer model spinning reels, and fish GTI conventionals on rods for drum and tog. Additionally, we fish some of the GLS series reels, too. Offshore, we have Penn Formula reels, and you can't beat the Internationals!
That being said, we also have some Shimano tackle that works very well! I have a Stradic that's been great to me over the years, and also one of the best small bottom fishing conventionals available is the TR100!