I talked to someone via "chat" on the Orvis site with this same question, using their Battenkill Barstock reel and their Clearwater reel as examples between the machined reel and the cast reel. The only pertinent issue he raised was the difference in weight; the BBS is about 16% lighter than its Clearwater counterpart. But if you look at the photos of the two reels on their site, you will see that the BBS is heavily ported on both sides, while the Clearwater is ported on one side only (and, it appears, not as heavily as the BBS). Therefore, I tend not to put too much "weight" (pun intended) on the difference in avoirdupois.

He didn't mention any difference in resistance to impact.

Any other input? Anyone?