Compared to the nexus 7:
Lower res screen, only ~5 hours battery life, reportedly stuttery performance, older version of android, not a nexus device/running stock android so slower updates, near-identical performance, higher-quality aluminum construction, camera, SD card slot.
If they were the same price the slate would obviously lose, but the 16GB nexus7 (they don't make an 8GB model any more) costs $200. I would still get the nexus7.
If I wanted to go el cheapo I would get the nook 7", which is $118 on amazon (8GB model) or $149 direct from B&N (16GB) and markedly superior hardware to either the nexus7 or the HP.