you need to check out the 3D Audio Mic Pre CD. Word of mouth and opinions are NOT the best way to buy a mic pre! (IMHO)
33 mic pres were used to record female vocal and acoustic guitar, blind test, very interesting. More info at: http://www.3daudioinc.com
and the CD is also available from Sweetwater. It's a good investment.
BTW, I didn't make the CD and don't sell it, I just really admire the project and the results it produced.