I have an X-22 stock and a Boyd's At-One stock on my Remington 783. I think I paid around $200 for my X-22 and I'm very impressed with it for the price. The adjustable LOP is simple and and sturdy. I didn't have any issues with comb height but having to buy other combs separately is a bit frustrating for me personally. I think they should come in the box with the stock. It's also very difficult to bed an X-22 stock as the plastic material doesn't bond well with bedding compound. I haven't personally tried this but I researched it a fair bit and that seems to be the common understanding. Outside of the bedding difficulties and the amount of time it takes to change the LOP and comb height, I really don't see any issues with the X-22.
My At-One stock on the other hand was a complete waste of money. I purchased mine with the target overmold grips that wrap around the front. Even with these "target" grips your hand is still well back from the trigger. I don't know how people could even use the stock with the standard grips. It's basically like holding a rectangular block of wood, very uncomfortable. The entire stock is blocky which I assume was to keep costs down. Shipping to Canada was $58 USD plus the tax I paid at the border. In the end it cost me around $400 which is way more than it's worth. The LOP and comb riser require a lot of force to move them and aren't flush with the stock at their lowest levels. I also had to spend a lot of time sanding the barrel channel down as it was way too small to fit my stock barrel. The target grips also don't line up properly and as a result there's a crooked gap where they're supposed to meet. I bought the stock for the adjustable LOP for when I hunt deer in the fall in varying layers of clothing. The 783 has next to nothing in terms of aftermarket stocks so this was my only option, looking back on it I should have just toughed it out another year or two until other manufacturers start offering options for it. From looking online it seems the quality of these stocks can widely differ. Not all of them require as much force as mine does to move the LOP and comb. I understand their other stocks are typically very well made but I was very dissapointed with the AT-One.