Should I use VBR NEW?

Is there a loss of quality if I dont care about speed?

Using Lame 3.98.2

vbr new is implemented in Lame 3.98.2 automatically. There is no need to force it. Using a command line of -V 2 --vbr-new with Lame 3.98.2 would be redundant, it would basically be telling Lame -V 2 --vbr-new --vbr-new. So you can just use -V 2, no need to worry about telling the encoder to use --vbr-new since it is already automatically using that.

You will need to force --vbr-new if you are using Lame 3.97. And no, there isn't a quality loss. The new encoding algorithm is thought to be "better" while being faster. Lame's encoding quality was not sacrificed to make it run faster.

the reason I ask is because FOOBAR prompts me, will it be the same if i check the box and not check the box?

Yes, it will be the same whether you click the box or now but only when using Lame 3.98.2. So you can leave the box checked if you don't want foobar2000 to keep prompting you, it won't hurt anything. Lame will see it as a redundant statement (just like saying the red car is red) and move on using the --vbr-new method anyways.

thank you, so I am assuming that box is if you use lame 3.97 or 3.96?

Yes, that box is more for use with older versions of Lame.