Funnily enough, I was also in the long haul between 3.15pm-4.45pm (Finnish time) on the same day as you (Wed 7th Oct). I had to move between the proper L/H J side to the other in order (and back) to find a working beer pump. Busy but not full would be summary - I had a comfortable seat at one of the higher tables and there were plenty of odd seats dotted around (although their did seem to be several large Japanese groups taking up a lot of the soft seats).

As for yesterday - unbelievable!!! We had access to both sides (travelling with my BA Gold wife), but the only 2 seats we could find together on either side were in the small side room of the short-haul side under a noisy airconditioning unit at an uncleaned table.

We retreated to the Schengen side - the Silver Wings lounge was over-capacity (although by resorting to asking quite sharply if all the seats were taken, we did embarrass some selfish people into moving their coats and bags - whilst some people were already perching on tables and standing ), the Tower lounge looked full as we walked back past after deciding the Silver Wings was uncomfortably crowded (we'd already decided on an alternative strategy by this point - see below), and the Gateway lounge is closed on a Sunday (why, when there is obviously such a pressing need for lounge space?).

Anyway, our alternative was to head back into the non-Schengen side (our onward boarding pass to LHR enabled us to do this) and buy a drink at the My City Helsinki bar between gates 35 and 36. Very nice space, with lots of comfy seats and not at all busy.

IMO, the whole point of a lounge is to provide a sanctuary from the less pleasant environs outside in the main terminal - at HEL, quite the reverse is true right now. Appreciate that the airport is in a transitional period at the moment, but I have to say that this did sour the experience of using HEL as a transit point somewhat (as my in-flight experience of Finnair was superb - hope to do a trip report soon).