Applying to graduate school at my undergraduate institution I did my undergrad at a school which is near the top in my field of interest, and I'd like to apply to its program in that field. While my application would certainly not make me a more-likely-than-not admit, I think it's competitive enough that applying is worth the time and money. However, the responses to a previous question suggest that applicants like me may be less likely to get in than comparable students who went to a different undergraduate institution. Should I take this into account when deciding whether or not to submit my application?

Some additional information that could be relevant:


I graduated last year, and have spent that time doing research at a lab which is not affiliated with my undergrad institution. I have done more research here than during my entire undergrad career.
I am not laser focused on a single research group at this institution, or even a single sub-field. Indeed, one of the reasons that I would like to apply is that it has strong research in more than one of my favorite sub-fields.
I'm also applying to a few schools in a related but different field this application cycle, and my undergrad institution has a strong program in this field as well. Does this discounting effect apply to admissions committees considering applicants who are changing fields?


Edit

In response to the opinion-based hold (which I don't disagree with), I'll try to ask a more specific question. Suppose my probability of acceptance at this top school would be p if I were coming from a roughly equivalent but different school, and my actual probability is q given that I did my undergrad there. What values of q/p are typical? I'd still like to know even if the answer is something like "it varies so much that the value could be 0 or even greater than 1", or "maybe around 0.8 but with a huge standard deviation." I have decided to apply already anyway, but I'm still curious.
Policies vary widely by program, but many top programs tend to encourage—and some require—that their students apply and attend other graduate schools. In part this is to encourage diversity in training experiences, so that students are not working in a single group for an extended period of time. I have heard of programs where they will admit their own students only if they haven't gotten in elsewhere (but students at such programs usually can get in somewhere if they are sufficiently qualified!).

As for the last question, again, this really does depend on the program. However, in most cases, I think the fact that you attended the same university but in a different department means you won't be viewed as one of "their" students, unless you were closely affiliated with that program somehow—for instance, if you did undergraduate research with a faculty member in that program.