Hello FT.

I was travel to BKK-KUL-PEK on Monday and stay airport overnight, to share the reference information in PEK airport.

Seat: 4k
23:52 Landing
00:01 Gate 507
00:06 Door open
00:12 Transfer immigration, zero people waiting
00:16 Security check, each line about 15 people waiting
00:25 Security check cleared

Who did not waiting in the transfer counter. But in my case, while boarding pass was already printed so the next morning to go to the HND with JL. I several times transfer in PEK, this time was best.

The gate of the E10 side transit hotel if there is a Priority Pass was the 3-hour free with public lobby stay. But it poor equipment and meal and do not use the shower. If paid accommodation you can also use the shower and 150RMB if shower only use.
http://en-shopping.bcia.com.cn/store/844.html

Gate E19 side of BGS lounge was food, drink, and facilities are better than transit hotel lobby. Shower can also be used for free, but I have become a pile the used towels when I went, it did not become to feel used.

Air China first class lounge can also be used in the Priority Pass. Best meal and equipment in PEK and shower is also use for free and clean. But can not enter with Priority Pass from 10PM until the 6AM.

If if the airport stay, rest in the BGS lounge and move to Air China first class lounge and take a shower after 6AM. I was also that way.

Note: Late night was weakened by the air-conditioning is the some location of the airport.

Have a nice trip!!