My Yamaha 01v only runs at 44.1 so therefore in the past I stayed with that so I could use the SPDIF inputs of the TAscam and then the 6i6. I have changed my set up and now use a Joe Meek 3 Q as my input for vocals, A Fender rumble for bass input. I use the 2 front inputs on the Scarlett for my guitars,, miked or DI'd. I also use small Mackie Mix 8 for cue mix so I don't really use the 01v anymore. 
I highly recommend something like the Mix 8 for monitoring. You can run the 3/4 output into it.  I have a second output from the Joe Meek as well as a second mike on my amp. It allows 100% LOUD control over your cue mix. 
 100's of projects are in 44.1 and I would rather go 48 as I do believe there is a difference but I'm not sure when and where I'd make the swicth over. 
I leave both my interfaces at a middle setting ( 256?)  and never change this. It seems to work for all the stuff I do both tracking and mixing. I haven't had a drop out in years. 
 
I do use a my 01v mixer when I record a live band with the Tascam. 
Because I need compression on certain channels I'll use the 01V for lead vocals, snare, kick and Bass. 
I'll use the SPDIF for the drum overheads because that's stereo.  
I use 11/12  13/ 14 fed from my 4 Aux outs of the 01v. and the SPDIF so there's the back 6 channels. 
Then the front 8 XLR get guitar amps, back up vocals and other drum mikes, The 9/10 I've used for acoustic guitar and Amp TRS DI outs.  Keyboards use the midi so there's all 17 channels. I also might use a stereo USB board mix feed and run Sonar in WDM mode ( now WASAPI ) so projects can have 18 audio tracks.  
 

I was under the impression that I can't use WASAPI.... can I? Never tried WDM either......
 
I've got more inputs than I use with the OctoPre MkII, especially since selling my Virus Ti2.
 
I've been wishing for a Mackie 1642vlz4, as I'd like 4 buses and direct outs. I've had a handful of Mackies over the decades, and not having a mixer feels weird! LOL   Like you, I've come from the "old school hardware days" (started playing in August '63), so my brain just "leans" towards that approach.
 
I often advise guys to read Ethan Winer's article on using a mixer with your DAW, but haven't had the funds to "straighten my situation out".
Michael
 
 
 

WASAPI or WDM Are fine for recording a band. Live Recording does not involve latency as everything is recorded at the same time so you could have 100ms of RTL and it would not matter, all the tracks would be perfectly aligned. 
You need to use ASIO for overdubbing and all other processes in Sonar.  Once you start overdubbing  latency matters and Sonar need ASIO to adjust the timing offset. All other driver modes do not report latency properly to Sonar only ASIO so they usually show up late on the time line.  
 

Thanks, Johnny V, that makes it quite clear and reminds me about RME I/O's using their own protocols. Jim Rosenberry pointed out that the MOTU AVB Ultralite has a usb RTL of 4.9 which compares nicely to the "RTL range", I'd like to aim for. I haven't had much of an issue with the Tascam and certainly not with the 18i20 (v1), but one can dream.
Michael
 

Oh wow, I thought they had long stopped updating this. I'm using an old version after tyring them all this was the only one I could get to work. Not without its issues though. I have to have the computer on a few mins before turning the tascam on or I get a blue screen of death.

I might try this new version though. Cheers.

I also assumed they'd stopped updating the drivers for this 10+ year old product and missed that this came out in 2015     I'd gotten the December 2014 update, but only recently went to Tascam to check.
Maybe they'll do it again!
Michael

Adji
Oh wow, I thought they had long stopped updating this. I'm using an old version after tyring them all this was the only one I could get to work. Not without its issues though. I have to have the computer on a few mins before turning the tascam on or I get a blue screen of death.

I might try this new version though. Cheers.

 
I have used my us1641 with at least 12 different computers from XP 32 bit up to the latest W10 64 bit. Under XP there where issues which in retrospect where probably the computer not the interface. But as a rule it never gave me problems. I bought my Scarlett 6i6 strictly for portability and at this point there is little difference in performance or stability between the 2 interfaces..  
 I've never had a blue screen and I always leave mine turned on. Try a different USB port.  

Yep. I have had smooth sailing with the 1641 since they stabilized the driver in XP, like 10 years ago!?!?!
 
Michael