Hi Phil,
I've been going to NL for a number of years now as the family have interests in a tourism business there. I'm not a surfer but a SUP'er so bear that in mind.
The previous comments are all valid. NL can get busy especially in school hol's, really busy. High tide is the time when everyone wakes up and starts heading out. This year I started heading out early to beat the crowds (around 3), it would still be shallow but i could get a few waves before the tide came up and the hordes came out. Mind you, easier on a SUP than a short board at that time. Yes all of those breaks can get very busy when its on. Shipwrecks seems to sort out the crowd when it picks up. A good mate of mine was there at the same time this year and he is a very competent surfer. Got it on an 8-10 day. Not a big crowd but heavy and got rolled a couple of times.
A couple of years a ago a bunch of us boys went up. The only short boarder was on a 6'4" i think ? We did have a pretty flat week and he struggled on this. There is a break at the back of NL in the channel between NL and Nusa Penida. I think its called secret point ? Surfed it once and defn big enough for short boarding, my mate did ok, plenty of guys out but harder to get to on a bike and jump into the ocean launch off the cliff or take a boat, so the crowd is more 'experienced' shall we say and you don't get the whole spectrum of surfers there to deal with, like you do at Playgrounds or Lacerations. I've heard that on a big day, it's big and i can certainly imagine that being the case. You just have to pull out before the seaweed farm
There is another break between Lacerations and Shipwrecks called Middles. It's a great right when its got size. A mate and I surfed it last year on SUP's for two hours and it was one of the best and most intense sessions I've had. It's a great right, the only problem is, if its a long ride, you end up riding over the old star pickets underwater from the seaweed farming days. At high tide there are a few feet of water under the board but it's a pretty sobering thing when you first realise what they are. It was an awesome session, but I had nightmares that night about what I had actually done. I've only ever seen a couple of guys surf it at once.
Either way, I think no matter what break you're on, if it's school hol's, it's going to be busy (and even not if it's school hol's sometimes). When it gets bigger, then that tends to clear the crowd out a bit.
We stay at Bali Hai beach club but it is expensive compared to other options.