Focusrite Scarlett 18i20 vs Roland OctaCapture

hi

I’m looking for a good multi-track recording solution for home studio to record several separate instruments simultaneously each track in separate channel for 8 channels, phantom power, 2 better 4 headphones, minimum 4 outputs, midi I/O to record guitar, bass, drums, synth, piano, 2 dynamic microphones for guitar and piano. within 500 bucks, but I decided to add a hundred bucks if it’s really worth it. but to understand it, I would like to hear your opinion or even better your experience from practice

I reviewed all of these devices :

Zoom R24 and Zoom R16
Behringer FCA1616
TASCAM DP-24
Presonus FireStudio
Mackie onyx mixer
MOTU 828 mk3
Audiofire
etc

but finally decided stop my choice on this two, so in the main I’m interested in Focsurite Scarlett 18i20 and Roland OctaCapture

about Focusrite Scarlett 18i20 I’ve done some research, I read manual, watched reviews, feedback and somehow I have idea about it. in this case I need to compare the quality and capabilities of these two devices and evaluate the advantages and disadvantages of both, functions, preamp, adaptability with a DAW and which DAW better, adaptability with PC system Windows 7 pro etc

now about Roland OctaCapture, I have read from two different sources about problems. one of this bad reviews is here http://www.amazon.com/Roland-OctaCapture-USB-Audio-Interface/product-reviews/B0048KM70Y/ref=dp_top_cm_cr_acr_txt?ie=UTF8&showViewpoints=1 does anyone know anything about this?

but the other hand auto-sens automatic volume adjustment of incoming signal is very convenient and 24-bit/192 kHz audio quality, 'm not sure that I need it but digital mixer control is also included in the list of functions of the device

It would be very helpful to hear your opinion about this two devices because since I must to make a final choice!

thanks