Nomad 1600 air shocks

[Happy65]

Hi folks,
New owner of an '05 here. We've put about 600 miles on it since buying it last week, it seems like a great bike so far. (my first cruiser!)

Sorry if this has been asked a million times, but the search doesn't seem to be working for me. The previous owner said he preferred to run the bike with no air in the shocks. What's the collective wisdom on that? Do it? How many psi? When my wife is on with me, we're probably pushing close to the GVWR. Lol. I've noticed the shock has bottomed once or twice on big pavement dips at 50-60mph (two-up). But I've never had a bike with air adjustable shocks, and I gather there's some debate on their merits.

Also, if I do pump them up, do I really have to jack up the bike first? Thanks