So the the lines/ridges are a function of the tool used (looks like 2 flute end mill to me), the depth of the last cut. Sometimes using the same tool path all the way to the bottom can add those ridges along the bevel edge too. Things to do to help that. Add a small offset/boundary to all the cuts, then add a final tool path (1/32-1/16th Ball nose is my preferred, or a new 4 flute 1/4" End mill for large flat areas), (use the multitool option in Vcarve). Group all our final cuts in one tool path (when you save), does not add much time, but cleans up all those ridges. Also allows you to make up time by using a large offset on the others as your taking the ridges off anyway.
Spindle - Biggest reasons - Can run much slower spindle speeds (so more options for tools and materials); next noise, typically much quieter (depends on what you are replacing). Does add cost and complexity (where to keep that water bath, and changing it frequently).
I have a spindle on one of my machines router on the other. The spindle is not enough of an upgrade for me to spend the money. But I do like it on my other machine and find I use that machine more , especially if I’m in the garage with it.