Nowadays sitting cross-legged at the base of the Temple of the Grand Jaguar is possibly the best way of experiencing it. At some point in the early 90s the staircase was closed off to clamberers.
This time I discovered that Temple II opposite is no longer open to frontal assault either. Instead a winding wooden staircase has been erected on the south side.
At present Tikal's Temple IV, the highest in the pre-Colombian world, is under-going a bit of nip and tuck and consequently, visitors are also unable to make it up on to the roof cone for the best view in the Mayan biosphere.
Some more pics of Tikal here.