To fully service bearings, you need to take them completely apart and strip the existing lubricant. After they are fully clean, then relube them. It's more work than just dropping in lube without taking the wheels off.
The Ron's lasted me one set of wheels (typical for any average bearing) with intermittant re-lubing. I mostly street skate, and most of the spots are dirty, so I tend to get more dirt in my bearings than normal. Once you get particles inside the bearing, it will generate more friction and eventually score the insides to the point that they are ruined. It only takes one session to damage them that badly. Lubrication won't remove dirt from the inside.
Thus, I buy the cheaper bearings and just push more to get there.