Hi Zo,
I Was an ARC and ARC2 user but never was satisfied with the slightly thin, hollow, harsh sound of it. I bought into SonarWorks when they were first announced.
Started with the headphone correction software for the AKG k701's and K240 studio. I didn't think the k701's could be any more clear/defined, in the mids, but they were. The K240's still had a little too much low end hype though. I mentioned this to the SonarWorks guys and next thing I knew was they released a modification so the stock correction curve could be modified by the user and I could now reduce the low end of the K240's. That's Customer Service! Latency, not so much with the headphone correction and, IIRC, it can be changed. Really don't need the headphone correction for tracking so any latency is a moot point...
I then purchased the speaker correction software. I was able to correct the speakers in about 15minutes and it had a very natural sound vs. ARC(2). Depending on the accuracy of the correction it will cause some latency but you can change this with a slider on the UI. I have no problem tracking on the studio monitors if I reduce the amount of accuracy and it still sounds much better the the prior product I was using. Seriously, I prefer tracking with the cans on so again it becomes a moot point...
I liked it enough that I then Purchased the Ref HD version for speaker correction at the desk and I still use the standard for the portable setup. The HD version may not be necessary but will allow more measurement points to be included in the correction file among some other special things that are mentioned on Sonarworks website.
In short, Yes, it can induce some latency but the sound is so much more pleasing than using the old product. I believe they do offer trials so you could try this yourself and there were several threads about it in this forum. IIRC some even used the ARC mic to take the measurements so they did not have to wait for something to be shipped.
You really should give it a try as it is all subjective...
Kind regards,
Rick