I've managed to 'luck out' with 387/2s a few times as well. Notably though, most of the times I've been on a 700, it's been the most appropriate train for my journey, I have only really had to bend my journey once, which was for my very first trip. I actually happened across one by chance later the same day.
700113 was a legitimate journey today and my first trial of first class (wanted a table for my laptop, probably wouldn't have bothered for a 387 trip, so there's £7 extra revenue for you :P). No major faults with the unit but there was a long dwell at Farringdon as the doors took 40 seconds to open and it took the unit a full 2 minutes to voltage change (notable by the fact the ventilation fans and power sockets in first were off for that length of time). I also observed the sockets being disabled during any loss of third rail power, e.g. crossing points and so on, as my laptop switched from battery mode and back to AC numerous times on my journey, which theoretically, may not be good for the devices plugged in? I might be imagining things, but I honestly don't remember this happening on Electrostars - is there a longer buffer time on those when running on battery power?
As an entertaining anecdote, the PIS system was working fine on 700113 on the way down, yet defective on 387127 on the way back (always displayed 'we are now approaching x' where x would be whatever was the previous station - never displayed the next station or the destination & calling points on the service, visually or audibly, which given the variation in calling pattern during the peak would see most customers reliant on an app, leaning out the train to catch a glimpse of a sign at a station, or hope they caught the calling pattern before they boarded.
