If you are flying twice a month, I think it is a no brainer. But your decision. I sure would invest if I were you, but then again I would be flying on Tango Plus too.
But word of warning, the free PCs in MLLs are often occupied and there are only a few of them. Often some lowlife takes on to work on his own laptop which annoys the heck out of me.
I wish MLL staff would post signs resticting the use for those who actually need to use the PC or put a 20 min time limit on them.
It is one of my big pet peeves as I depend on using them and refuse to carry a laptop with me!