The C414B-XL II is supposedly set up to be better for vocals. The C414B-XLS has an ever so little darker eq curve. Basically it is up to you which you like better. There is an audible difference between the two but neither is superior to the other by definition.

The XLS was designed as a (more-or-less) direct replacement for the C414B-ULS, which is transformer balanced and has a flat response (+/- 2db or less by spec, I believe). The XLII replaced the C414B-TL which is transformerless, and has a gradual HF "lift" starting at around 5K. Aside from the HF rise, the B-TL / XLII also exhibit a slightly deeper bottom as they are electronically balanced.

I went with the XLS based on the thought that if i needed to add a little more upper mids i could use eq to do so. therfore leaving me with a more versitile mic. I am happy with the mic and think it sounds great on vocals as well as evrything else i've recorded with it. This is the Best mic in my collection and i had to keep versitility in mind because i could only afford one 100 cindenser at the time. Go with what u think sounds the best.

ps $1000 condenser, and i guess you could use eq to lower the upper mids on the XL II just as easily.