It's not because they're not good, it's just because I can't be bothered reviewing them. I intended on doing a review similar to the Vittoria XGs, but these aren't going to get to 1600 miles for a long time. These ones are going to be as per what a normal person is like with bicycle tyres: Fit and then forget.
I mainly got the XLs just because I fancied a change from the XGs and at the time I switched it most certainly wasn't the right time of the year for the XNs (I'm a bit sad I never got to try those). I had hoped that the XLs might be a bit faster on smooth surfaces (roads) because the centre tread pattern is more continuous than the XGs, but I honestly noticed no difference - if anything slightly higher rolling resistance, but that could easily be my imagination as it is hard to compare to a tyre from half a year previously.
And so that's my review: Not really any better or worse than the XGs.