Auctions online are a piece of cake with good software. I left the league a number of year ago but we had one on CBS and even back then it was excellent. I am not a fan at all of anything else CBS does so for me to admit that means a lot. MFL looks to be a solid option as well. In person you want to have either a very experienced auctioneer if they are also an owner or, far more preferably, the first year or two have a non-owner run it. There's a certain groove/focus you need to maintain keeping up with the auction tasks and while that part is easy enough, it's also very easy to ruin your team because you aren't able to balance your attention properly.
Auctions are a ton more fun in person than snake because they are much more immediately interactive. When team 3 makes their first round pick, they immediately grab their tablet, make a phone call, go for a smoke, whatever. They come back in 15 minutes - am I up yet? No? Browse 4chan. Now? You can't do that in auction Nearly every player is in play for every owner, at least for the first 4-5 bids. You may hate early QB's but I bet my last dollar you'd take Brees for 5%. Once a guy gets priced out for you you're busting ### to get to the john to take a leak because if they nominate your key sleeper next you need to be there to get your 2% bid in.
Auctions are exponentially more strategic than redraft and heavily favor better owners. Bad owners get abused in these things, especially if it's a salary league where the salary is tied to the bidding process. My homer has a couple guys pushing for auctions but we have a bunch of very casual owners that, while not entirely bad, would still get abused by a few of us more hardcore owners so I have never really endorsed the idea.
I wouldn't say they take any longer but the only live draft I do now is a semi-casual homer league in our 21st year and the hanging out and chatting part is at least 40% of it for us, so there's no urgency for us to get it in. We don't have a pick clock and some guys take 5-6 minutes to make a pick.
If you want to do a litmus test, do your standard snake draft as normal for 10 rounds then do the rest as an auction. Give everyone a $50 pool and that money means nothing after the draft so they may as well spend it all. There are enough meaningful players and sleepers at that point that they will get a very realistic idea of the nuances of it.