FFMPEG conversion quality

So if I convert a video with FFMPEG, with the most basic command:

ffmpeg -i video.mp4 -y video.flv

I get a low quality version of the video, but it streams quickly (the buffer loads really quickly).

I can fix the quality completely by pumping up the bitrate to 2000k+ or so:

ffmpeg -i video.mp4 -y -b 2000k video.flv

But then it streams really slowly even though my connection is 10+ mbps...

I can also do:

ffmpeg -i video.mp4 -y -sameq video.flv

But it streams slowly too.

If I stream the original file (before it has been converted) it streams fine and with good quality.

Does this have to do with compression or something? I'm new to this stuff so I don't really know what I'm doing. Some explaination, advice or an ffmpeg command that would do the job better would be super helpful.

Thanks a lot!

Help pleasee!

Bump.

This hasn't a thing to do with PHP. Quality of an external program falls squarely on the program and not on the caller.
Moving from PHP to computer discussions.