The stock one on my old RC8 I found to be fine, held my QHY9/FW/OAG/Reducer and did the job. I have heard some people strip apart the focuser and dip the bearings in kerosene as it naturally cleans and lubricates the parts, and found it to work much better.
The question really is - does the current focuser work for *you*? If you find it does and no real issues, then I would say stick to it. Horses for courses
