Nice! It appears from the photo that your machine is in alignment. Faceting is a much slower process than cabbing. When you consider that you are cutting a stone to a specific design using specific angles and depths for each individual facet and you must do that whole procedure for each grinding and polishing step that you use, it can take quite a long time. It all depends on the design (how many total facets are in the design? A single round brilliant or a Portuguese pear cut?), the hardness of the stone you're cutting, and the size of the stone. Larger stones take considerably more time because you must get all the scratches out of each facet from the previous grit out before you can proceed to the next step.
Here are some good articles to read:
http://www.attawaygems.com/NMFG/mystery_of_polish.pdf and
http://www.attawaygems.com/NMFG/cabinet_makers_and_chain_saws.html regarding grit size and subsurface damage.
Regarding your laps, if the 600 is a diamond plated lap, then it will wear out eventually and need replacing. You can replace it with a 600 topper plate to save some money. The time it takes to wear out a lap depends on how you treat the lap, the hardness of the stones you're cutting, etc. You should get considerable wear out of the lap before it needs to be replaced when buying new. Since you have used laps, it will be difficult to tell. Always clean your laps after you use them and make sure they're dry before you put them away. Store them in individual containers (zip-lock bags work well) to avoid cross contamination. Nothing sucks more than starting the next grit and getting a big scratch across your facet.
If you have laps that can be recharged, you would recharge them when the cutting or polishing slows down. Hope that helps.
