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I am going to buck the trend and state when I am doing a Title 24 model I use CBECCcom as the modeling tool of choice. Workflow is typically geometry in OpenStudio -> Export SDDXML to CBECCcom.

I've use IES and Epro as well. Both had significant, though different, issues in my experience. For IES the HVAC systems must be either built twice (if needing to use Apache engine) or only in the CBECCcom portion if only needed for CA T24. EnergyPro I found elements to be lost in translation from EPro to CBECCcom simulation - building orientation being one. EPro is also only a 2D element, so geometry can take a while. Epro uses 'absolute' wall reference system, which is fine, as long as the user knows this. But I commonly find that the north arrow on plans magically changes on some projects...hummm....anyways, the above are reasons I've got almost exclusively to CBECCcom. We do have a few uses who use Epro, but its based on their experience with it.

A major plus is that with CBECCcom we can work on the 'back side' in NotePad++/text to create/replicate many of the systems. If I have 10 AHUs, I can build one in CBECCcom then replicate this on the text side(w/ renaming) very quickly. Same for luminaries or other lighting systems. I've also been able to use RegEx to help make changes to big model files as well. The other nice thing is that within CBECCcom you can select to have it save all of files used in simulation (ex: E+ files) then go look at these to see what was actually simulated. This is especially true for the Baseline building. This may be an option in IES or Epro, unknown, but it has been a huge plus for native CBECCcom.

The workflow above of OS-> SDDXML -> CBECCcom also allows the use of some measures OA measure to help with things. Namely the creation of thermal zones, renaming zones/envelope elements. OS also has access to the CAT24 approved constructions, so this is also nice if a visual 3D reference to assign constructions on a project with multiple constructions is wanted/needed. I haven't taken the time to build a CA T24 construction/construction set in OS, but I'd bet it'd be super useful and awesome. Note: I am not an expert OS scripting super guru. The scripts above are some that come pre-packaged with OS.

Since all 3 run an EnergyPlus simulation, I wouldn't imagine there to be a huge difference in simulation time. Probably some difference in 'translation time', but I haven't studied this.

At the end of the day, the 'right' software is the one you feel comfortable with and fits a workflow that makes sense.