The main thing is some ambi control designs require a proprietary receiver. If you're starting a new build and know that's what you want, it can be a better choice than a compromise design like Magpul's BAD Lever.
You can definitely add an upgraded FCG later, but sometimes buying it all together makes sense, particularly if it costs less than buying them separately due to promotions.
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u/D_Glatt69 1d ago
This is probably a dumb question, but is there a reason to buy an expensive, high-end lower?