Was hoping I could ask a couple of quick questions about my next home security build. We've built a new house and I'm adding an alarm to my home security/automation compliment. I've installed a couple stand alone Vista 20p systems in the past and while it's been a few years, I'm not to worried about building a setup. What is primary for me is the ability to control the system externally so I can integrate it with a LinuxMCE build. It seems like DSC alarms have received a good amount of focus from the open-source community. Even EnvisaLink appears to have focused on the DSC systems first. Please forgive if these seem basic but I've read more forums and blogs about the latest trends/opinions in the diy alarm world and I just need some advise to kick me over the edge one way or the other.

So my questions are:
1. Can the envisalink provide me the ability to gain local access control of my system?
-Local access if the most important feature. I understand the TPI will allow me to send commands to the envisalink locally to control the system. I can write the UI and backend code to control it; I just need that api published. In my reading, it seems like this is available but want to make sure.
2. From an Envisalink perspective, is there any reason to consider a Vista 20p over a DSC 1864 panel?
-Despite having some comfort with the Vista panels, neither seem terribly difficult to setup. Just muddling through the documents and taking the time to understand/do it right.
-Curious if the DSC panel is more feature rich than the older tech Vista panel.
I do appreciate the time and advice!