I would go with the HP G6. It is a better overall machine.
(HOWEVER i cannot confirm, post the links or the specifications of the machines or even better, the model number of the laptop.
In terms of durability, wait for others to post and go to mr google and search on HP and Lenovo laptops on how long they last and so on.
They should last about you about 4/5 odd years. You hear IBM etc. for Lenovo, I had a AMD cheap HP laptop for work I bought don't like it.
Depends what you wonna do with them too.
To make them last longer, look at guides etc.
How much you are you spending? I would suggest posting a new thread with your budget but first read Laptop Buyers FAQ on the forum before doing so.
All the best,