The main reason why I climb mill, is because of tool flex. If you conventional mill, the tool flexes to the inside, as to decrease the dimensions of your part (=bad). If you climb mill, tool flex is to the outside, so there are no worries about ruining a part due to your part ending up to small. Usually, my process for milling is...rough pass with roughing cutter, finish pass with same roughing cutter, then finishing pass with finishing cutter. If you were to conventional mill using this same strategy, then any time you needed to tweak your feed rate, or spindle RPM, it would have a greater impact on the next step, because of the tool flex amount, such as--to much material needing removed for the finishing pass (bad), or not enough material left to even have a finishing pass (ruined part bad). There's simply a lot more time/aggravation/risk to tweak a conventional mill tool path, rather than a climb path. That's my opinion on it, anyhow.