The performance isn't terrible. It's just not what it's going to be yet.
With early firmware, I found performance to be equal or better to the RT-AC66R I owned prior to this, with the one caveat that Tim described: radios disabling occasionally for no reason --or at least, maybe not disabling, but losing WAN access. I also would argue there is no "cheating" here --cheating would be a new firmware that actually makes performance look better than reality (e.g., manipulating Speedtest scores, or falsifying its SSI). Bug-fixing is not "cheating", it is bug-fixing and improving functionality.
Gary of ASUS (this is public in the forums already) provided everyone with a link for the 2061 firmware (up from the original 1179 and then the 2044 update) which has the Quantenna performance driver in it. I have seen improvements in a short period of time with this update. I wouldn't say that firmware is anywhere near its peak yet, but the unit is noticeably better than it was a week and a half ago.
SmallNetBuilder Forums - View Single Post - ASUS RT-AC87 Firmware - Official Releases
If you've already got an RT-AC68U/R model, I'd probably wait. You've got a dual-core CPU that supports OpenVPN client/server options reasonably well (which caused a fair drop in the lower-clocked single-core RT-AC66U/R's performance). If you don't, and your budget is flexible, I'd probably go with the 87, at least if you plan on running VPN, as support is developing quite rapidly (faster than any router I've owned before) and you get the best CPU performance of any ASUS model available, with more to come as the firmware reaches maturity.