no, the mayor problem of setting lossless quality is it's data straem over the net. Over which kind of net are you streaming? you could have 54mbps (in the best of cases) on WIFI G, 100mbps on some ehternet, or 1000mbps ehternet. When you are watching the streaming content, press select button and see the data rate from video plus audio and check the sum is't being grater than the maximun bandwith of your network. Also remember ps3 doesn't have WIFI n.
i made my experience, and i could tell that on 100mbps network , the best thing to do is to set keyint=5:vqscale=1:vqmin=2 /* Great quality */ in wich case the data rate never get's more than 65mbps
in lossless mode, watching 1080p AVC + dts 5.1 MA core (1.5mbps) , the data rate gets near 120mbps for moments... (the video is variable bit rate) so, only gigabits networks could stream that ( you could do for example set a point to point network if your laptop has a gigabit ehternet, the ps3 has it)
PD: mbps = Mega Bits Per Second and Sorry for my english