I have 8 shimano baitrunners, 4 4500B and 4 6500B and I wouldn't give them up for anything. I have been using some of them for over 5 years and I have never even put grease or oil in them. One time last year I opened one up to see if it needed any and everything looked good. I have bankfished with these before I had a boat and have dropped them in the sand, but if you take the spool off and look inside there is no sand in there, they are completely sealed. These reels are designed for saltwater fishing so everything is sealed. Dont worry about which one has more bearings, if you ask me the more bearings you have the greater chance of failure. If the bearings are well placed and of the proper quality it will last longer in my opinion. I dont know how many thousands of pounds of catfish I have caught with them over the years but they continue to be great reels for me. I bought some baitcaster set ups last year to try them and they already have problems, I will be putting them aside and buying more baitrunners because they NEVER have problems. If you ask me, for the quality of the baitrunners I wouldn't have a problem paying even more for them. With the baitrunners you get more than you pay for, try one and you'll be another person won over by shimano quality.