Help - the best interface for X1 (price up to 600 Euro / 700$) used - which one?

Hi there, I'm wondering about changing interface. For now the choice (used gear) is: Focusrite Liquid Saffire 56; MOTU 828 mk3; TC Electronic Konnekt 48; M-audio Profire 26. As you can see - all of them have 8x8 in-outs and 2 ADATs. For now I have Edirol M16-DX and (to use as a ADAT 8x8) Adirol UA-1000. So - my question is - which one will be the best for working with X1 on PC. I use interface and Sonar as a mixing console too, not to record track by track, that's why I want to change gear (for now I have 14 inputs already busy: MIC, guitar, 6xTRITON, 2xZ1, 4xMicroX) and I want to do some external processing... Any advices?

and what about latency? I readed that FOcusrite is the slowest (worst) in latency - 256 to 512 with full load; and M-audio is the fastest one... Here I have an oportunity to buy M-audio or Motu in the price under 714$, Focusrite - 821$, TC Konnekt 48 - in US - 680$ - the difference isn't to big, so that's the reason of my question. As I wrote before - AT ONCE I want to use 16 inputs (minimum) and RECORD with listening post-DAW without significant delay.

There you have it. Now, the choice is whatever your preference is, go for it.

I love my MOTU MKII, ( 8 Ch version )

But also have the M-audio Fast track.
( 8 Ch version, USB 2.0, seems to work very well )

Still like MOTU much better !!!
Excellent drivers, GUI, nice effects built in, Mic preamps are good,
great latency. 
Have fun.

Don B
Q6600 desktop, i5 laptop, Win 7/XP, 32/64 bit, Sonar X1C/8.5.3

I was thinking about TC and Focusrite, but overall latency is the clue, as I want to play/record guitar with Guitar Rig plugin and hear the results. So everything exceed 10ms (128 samples in 28kHz/24bit) is out.
I know Focusrite is great, but - I heard - it has problems with latency.
In a fact I would never thinking about changing my Edirol M16-DX, but it has only 2 outputs, so forget about external processing.
Moreover, on PC, when I want to use both edirols simultaneously, I have to use asio4all drivers, so to have sound without clips and chokes - I have to increase latency......

octacapture best bang for the buck in all area     

I don't want to use "several" octa capture - I cau use "several" Edirols.

But I want to have ONE main interface with ability to plug in two ADAT expansions.

I don't want to go into 828mk2 because - as I wrote before - difference between mk3, TC, M-audio and Focusrite here is about 150$ - all of them are from 680 to 820$, so difference isn't to big.
I don't plan to use any EFX in interface, as software versions are better, I don't plan to use interface outside studio to recording - if using outside - just for liveacts with Ableton, not Sonar.

The best advice would be your experience and screenshots with latency settings of your interfaces in Sonar - or just - you could write here, how it looks in your case.

For now - Edirol M16-DX works with minimal latency 96 samples in 44,1/24mode the same Edirol UA-1000.
Both on ASIO drivers.
On asio4all drivers I set the latency to 112 or 128 samples, but it sems that even when CPU load is under 50% they have problems with smooth reproduction of sound.

Zo,
sometimes I like to read your posts, and sometimes you're just "out of tune"....
like this time.

The lowest latency setting for the MOTU-MK3 in ASIO mode is 64 samples. 

With my system specs (see my signature) I can run the largest SONAR Demo songs (which have multiple softsynths and effects) at a 64 samples latency setting with no drop outs or very little pops and clicks, if any. Just smooth performance with my MOTU UltraLite-MK3.

I run all my projects at 64 samples with no drop outs or pops and clicks, as my projects usually never have more than 20 effects and/or 7 softsynths, or 30 audio tracks. And that's with no freezing of tracks/softsynths/effects. 
 
MOTU products have a reputation of great drivers support and solid performance at low latency settings, man.

The driver will determine what the lowest buffer size is eg 64 samples.

Whether your hardware and software combination can use that buffer size without clicks and pops is another matter altogether.

Looking at your specs it looks like you should be able to get down to that level.

Wonder why you haven't mentioned anything like an RME FF800 which you should be able to get 2nd hand at around your price range. Just another option.

@ mudgel and thomas:
I live in Poland, so if I would like to buy 2nd hand RME i have to buy inside Poland or inside UE.
No sale offers in Poland now, new unit costs more than 1200 Euro (1715$). That's over 2x more money I can spend.
Import from US isn't the best choice because of tax and custom: 27% of the total price (price in declaration + shipping costs).

English isn't my native language, but writing (i.e.) here helps me to use it better ;)