Just an update in case people are curious, how the pandas feel with different springs:
78g (soft clear) - makes it stable but the heavy spring pretty much get rids of the tactile pump in the inver housing of the panda. Becomes a more"stable" halo clear true basically.
default spring (inver) - snappy and tactile but very easy to bottom out hard when pressing,given that the pump is so tactile and there is momentum after it.
with springs frrom early 80s vintage blacks (probably 68-72g?) - omg this is amazing, has the tactility still but hard bottoming out just good reduced by a good chunk. It may be a very few grams heavier up top than default but it is hardly noticeable and still noticeably lighter than a hako true or clear...and it actually has tactility unlike a "heavy linear" switch like the hako/halo. very stable to on pressing down - almost no wiggle, more stable than a zealios v2 78g I have which is about the same as the default panda.
60g soft - will test with a noticeably lighter weight soon.
off topic a bit but I put my panda springs into the vintage blacks I had and they are smoother and lighter now (the blacks) - so smooth in fact that after a while one can forget the keys exist. and I put the black springs as stated above into the pandas. With the lighter panda springs the blacks are a bit lighter at top but still not as light as reds (which is a good thing) but maintain control throughout and the smooth linear force curve makes any bottoming out on the linear blacks this way feel never too hard. I am not a fan of pure linears as I do want some form of pump response but man those blacks are really smooth now.
