When I did my open water class I intentionaly tried all the variations of equipment i could get my hands on. I used a different set up every time I could... Gauges VS computer, Jacket VS Backfloat, Octo VS integrated, etc.
I ended up getting a backfloat Seaquest Balance with Air II on it already.
My thought is that you should at minimum have a rough idea what equipment is out there that you could bump into. You REALLY need to make sure you understand your dive buddy and your own equipment before you hit the water.
If you follow my signature link into my divebuddy account you can read my blog about this topic.
My instructor in class told us to make sure and inspect and review with our dive buddies before any dive. Including goals of the dive, hand signals to be use, and each others equipment.
When I did my open water checkout dives with another instructor... He told us not to bother when he over heard me ask my assigned dive buddy if he wanted a review of my equipment.
Durring the underwater out of air drills, I'd give over my primary after I did a quick switch to the air source... Instructor tells me at surface... "You don't give up your primary!" My reply "Integrated air source, Yes i do!"... "Oh... ok."
Then when my assigned dive buddy did underwater rescue he would fully inflate my BC as his instructor had told him to do with a jacket BC... Well with a backfloat you DO NOT fully inflate or you'll never be able to turn them over to do rescue breaths. I lay they bubbling at the surface relaxed and waiting for him to figure it out, after a little bit I pulled out my reg and whispered "its a backfloat BC, let out some air." The instructor heard me and said "Shut up your uncounsious!"
On another dive trip one of my assigned dive buddies had borrowed equipment. I did my normal inspections of all our equipment. It never dawned on me that the guy who said he was PADI open water certified for many years, had never used a dive computer before. When I did the first group (3 of us) air check, he couldn't reply... He didn't even know what to look at on the screen! I ended up giving him a crash course on reading a dive computer at 25 feet with nothing but pointing and my dive slate. I still just took the dangling computer every little bit and read it myself because he didn't know how to indicate his pressure that either of us could clearly inderstand. Guess he was day dreaming when we were talking about signals on the boat pre dive... sigh.
So, MY take... you need to understand the differnt equipment your going to run into...the sooner the better. If all your getting is a quicky resort class. You probably should sign up for an equipment specialty class when you get home from vacation.
Whats that old GI Joe cartoon line? "Knowing is half the battle!"
Even if a new dive buddy just dismisses equipment checks and communication reviews... do it anyhow. Take time to see what they have on their BC, where equipment is hung, what they carry, how they mounted it... If nothing else you might get a new idea on how to rig your BC.