I try not to keep more then around 300K. With that I can either get 2 F tkts between DXB-USA or one STANDARD AWARD F tkt for my GF to fly to the US. this is all I use my miles for anyway & I always book last minute so LH F is usually avail for me.
There is no point in keeping millions of miles in my account since I must BUY a tkt (usually with EK in F) between DXB-USA every month so any time I can use LH for free is thousands of $$ I save for me & my company. (It must be LH F though, I tried UA last week for the first time & won't do that again (to much hassle, ground product sucks & IAD is out of my way since usually going to NYC (JFK). No other *A carrier can get me from DXB-USA with 1 stop in F