Just to pile in we visited CT in either 95 or 96 - before the ferry and the cards and the tickets and had the experience people are looking for now and can't find. Heck, we showed up in Monterosso in June without reservations. I try not to discourage people from going but try to temper expectations. My coworker really wanted to go and did everything "wrong" - visited as part of cruise excursion and loved it. If I had told her not to go based on my history she wouldn't have gotten that experience. Honestly speaking I would tell people not to go, but who am I to dictate what people want to see.
A few years ago I spent 3 days in Porto Venere and chose to leave that memory where it was and not visit again. But from that experience I would advise people who are looking for a new adventure to explore the southern side of La Spezia bay instead. Tellaro is a tiny CT like town all on it's own and there is sleepier San Terenzo and resorty Lerici connected by the walkable strand. And there is also Sarzana just over the hill connected by bus like Tellaro. All Italian beach towns are touristed in summer but the southern side of La Spezia harbor is Italians in for the summer not day trippers from cruise ships.
My next Ligurian adventure is hopefully going to be staking out the coast between Rapallo and Levanto and investigating Chiavari, Sestri Levante, etc. for at least a week and hopefully a couple of weeks.
I have had the debate with people if we are ruining places by recommending them and turning tourists onto them so that they "become touristy" and we risk losing the places we fell in love with. After I got back from my first, life-altering, trip to Italy I read a bunch of books with people's experiences in Italy and in one a woman returned to find her Italian family and stay with them. At one point an uncle goes on and on about how wonderful Rome used to be before they ruined it and she suggested maybe she shouldn't go to Rome. Paraphrasing:
"You have to go see Rome it's the most amazing place on earth!"
- "But you just said it had been ruined..."
"Oh it's been ruined so many times before it doesn't matter."
Is CT ruined? Yes, but it was ruined by pirates, and war and poverty and now tourism and probably by something else down the road. You can only visit places as they exist now and take them on those terms or choose someplace else.
Everyone have great trips,
=Tod