My home has a DSC system, keypad is simple not touchscreen (don’t have model number with me). Do you guys know if I can migrate that system and all of the sensors, sirens, etc to Qolsys? I believe it’s the same panel DSC is calling the DSC Touch and hoping everything would be compatible rather than having to go with all new stuff. Thanks.
Happy to assist! Typically you can take most existing components and reuse them with a new system (other than control panel/keypads) but what you would need would depend on the type of sensors you have with the system.
Are they wired or wireless?
If they are wireless DSC sensors, the DSC Touch (DSC version of the IQ Panel) should be directly compatible. Best to check the model numbers on a couple sensors to verify.
If they are wired, any panel would provide a fairly equal opportunity.
Qolsys (GE Version) could be used with the Hardwire 16.
2GIG or GC3 could be used with one or more Takeover Modules.
Not sure if the sensors are wired or not, we are purchasing the home and not in it yet so I will find out.
What are your thoughts on Qolsys vs. 2gig GC3 vs. the new upcoming Qolsys 2nd generation (and whether may be worth waiting for). I’m coming from a 2gig system now but the older panel. I have no experience with the Qolsys panels. Might be telling if they release firmware updates more often, etc…
What are your thoughts on Qolsys vs. 2gig GC3
I am excited to provide support for both equally. 
They are definitely different approaches in many ways. The GC3 feels like a refinement of the GC2, rather than a completely different panel. I would say the screen is improved on the GC3 (capacitive) beyond that of the Qolsys IQ. Qolsys has a lot more compatible equipment for it at this time, uses more secure GE protocol sensors, and firmware flows pretty quick for Qolsys, 3 - 4 times a year it seems as opposed to 2 typically for 2GIG.
vs. the new upcoming Qolsys 2nd generation (and whether may be worth waiting for)
We have no experience with this one yet, so pretty hard to say anything solid. It looks to be a refinement of the Qolsys IQ panel, and to include some of the features the IQ panel was aiming at but never got off the ground. It would be brand new in your case as programming/menus are laid out differently than 2GIG. Coming from 2GIG, the GC3 will still be pretty familiar.
Any thoughts on which brand has better home automation integration (locks, lights, etc…) I’m not super impressed with the GC2.
GC2 offers, I think, the best options. Has the widest compatibility with other controllers and devices.
Qolsys also has a pretty wide compatibility list, much bigger than the GC3 currently. This is regarding officially supported devices, of course. Qolsys and GC3 both have the UI for adding as a secondary controller, but Qolsys is not yet functional in that capacity (upcoming firmware) and GC3 is fairly untested.
Lighting modules are fairly simple and compatible all around.
What does adding the panel as a secondary controller mean? I assume using something like wink or smartthings as the primar controller?
I assume using something like wink or smartthings as the primar controller?
You assume correct 
Using another primary controller can afford improved local scene control and more wide-ranging devices and still have ADC control over ADC compatible devices.