Heyo!
On Y510p: +24GB SSD,Better vga(not a real difference),but not 17" display,4GB more RAM. Its known lenovo's touch pad is still crap.
On HP Envy: 17" display, 4GB less RAM.
So 12GB RAM is far enough, that 24BG SSD is a low qaulity slow one imo or a hybrid. There is a minimal difference in...