Wow, the staff certainly went WAY, WAY above what I would consider normal, even for an Emerald when travelling in F. They must have put some serious effort into having everything working so smoothless, especially considering your delay and everything.

That's even above what I'd consider to be offered to the highest elite tier member when there is a super-elite category (say: HON member on LH, IO on EK..)

Basically, under normal conditions, 1hr 40min on two tickets from T2 to T3 is a 80%++ guaranteed miss (even for an experienced traveller. 99% for someone less experienced), at the very least.

The airside transfer from T2 to T3 (and vice versa), while it exists, is cloak-and-dagger and personally I'd never count on being able to take it. They really got you the VVIP package there..

On the risk of repeating myself, I'd consider 4hrs for any T2<->T3 transfer on separate tickets to be of reasonable sanity (I-I) - cutting things a bit closer when you're holding a Chinese visa (or don't need one) and/or being reasonable experienced with transfer in PEK and not arriving at peak times (early morning 6am'ish being the worst to arrive at T3 imho)

For a non-rush hour transfer for an experienced PEK-traveller, no check in luggage, with a visa on two tickets (without the ability to get the second boarding pass ahead) I'd consider 3hrs to be the absolute sane minimum leaving a bit of extra time to feel "just ok" (not comfortable..)

For basic calculations lets assume both ways are the same (They're not. You need more time in T3 to reach to/from the gate than in T2, but bus transfer is quicker from T3 to T2 than vv etc.)

Arriving with 3hrs to spare -> 30min time to reach the terminal (either by bus, long taxi - I've often had up to 20min and 30min definitely is possible when you got a bus. Usually quite OK when in C/F, though). 30min through immigration till landside (Immigration can take longer/shorter, but during non-rush hour 30min is about the worst that can happen) - 2hrs till departure. That leaves about 1hr for the transfer to the other terminal, which is doable even if you just miss the intra-terminal bus in any case. But it won't leave more than about 30min for anything else.

So you were incredible lucky and I can guarantee you that you only made this connection because at least one staff member - but probably the whole PEK-team - did an incredible job.