RC, we discussed this at some point. The only fleet the 'cruiser limit' has ever mattered in was orks, as players run out of choices at around 1200 points when they've purchased 6 terror ships. Preventing cruiser spam.
The limit is somewhat for flavour, but it really doesn't do much as if one were to take all dauntlesses, they would still reach 1320pts, then you would naturally include a commander, and some escorts to fill it out, or maybe a dictator.
At 3000 points (with orks this sucks, as once you get 6 kroozers and 3 BCs/BBs... then you're a little stuck), people actually start feeling it. I played this against IN, and it essentially ensures a variety of things to be taken in the fleet, rather than just cruiser spam.
I think I remember 5-6 years ago someone on the old SG site wrote about how Chaos cruiser lists were the greatest thing around, and there might as well not be any heavy cruisers or battleships, and that the same thought could be applied to IN. Strange thought, but then again, the best Chaos lists of official rules are often all cruisers, and perhaps a hades/acheron. For IN the best ones avoid battlecruisers and simply take an Emperor and cruisers (or oberon). Sure some like the armageddon. Still...
Naturally for orks the best one was TS spam, another cruiser spam type. Necrons, spamming the scythe