differences between wadia 15i and 25 dacs

Hi, i'm trying to find some info on these dacs. I had a wanted ad on a-gon currently running for a wadia 25 but have since modified it to include a wadia 15i. I'm currertly using a wadia 6 as a transport thru a cal alpha 24/96 via the '94 vintage wadia glass cable as this combo enhances the top end's musicality but sacrifices somewhat in the imaging and soundstage areas. I need a 2 box setup as i run my bluray and fiber optic cable tv thru it and i'm also considering an i-dock or digital server in the near future. I've read some other posts that suggest that the dac section of my wadia 6 is similar to the wadia 15 but the i upgrade takes it up a notch, i know the 15 is a 20bit 32x oversampler and the 25 is a 24bit 32x oversamplerand technically the 25's resolution should be better but is this actually true? my wife and i prefer a musical top end so would the 15i be better suited for us? the rest of the system includes 2 modified hafler dh200 monoblocks that are going out to musical concepts in about a month for full signature upgrades with platinum front ends and his new power supply upgrade[ 4 jensen caps with a dedicated cb and 1000 watt torroidal ], juicy music peach 2 preamp, mit oracle v1.1 between dac and pre, mit oracle v2.1 between pre and amps mit magmun m3 speaker cables and aerial 10t series 1 speakers, 8 bay adona rack with mdf/granite shelves and adona mdf/granite amp stands under the aerials. so if some of you veterans out there could offer some guidance it would be much appreciated. happy listening, woody