Interfaith dialogue, for me, is not about "seeking middle ground with Evangelicals", as one has put it. It's simply about seeking mutual understanding. The divide is the divide. It can't really be narrowed. However, some peoples' perceptions of that divide are extremely out of whack. Indeed, many might need to narrow the divide that exists only in their own understanding. In other words, interfaith dialogue has less to do with “bridging the divide” as it does with defining the divide accurately. A good place to start is understanding what actually constitutes (in descending order) "traditional Christianity", "Evangelicalism", and "Calvinism".
For me, interfaith dialogue is about better understanding the facts of what both "camps" do and do not believe. This is why "How Wide the Divide?" was a watershed. False witness is being born, whether intentionally or not. My initial motivation was to stop the perpetual dishonesty I sensed from the counter-cult movement in regards to Mormonism. That motivation gradually expanded as I learned that counter-cultists (most of whom happen to be Calvinists, by the way) do not represent well the larger Evangelical community (including many Calvinists), and I began to have a desire to truly seek mutual understanding with good Christians of similar mindset.
That's why I recommend all "camps" read "How Wide the Divide?", to better understand each other and to recognize where we actually ( and perhaps surprisingly) agree, and where we indeed have disagreements--some of which are very significant.
For too long, too many traditional Christians viewed Mormonism through the filter of the counter-cultists. Likewise, many Mormons have viewed many traditional Christians (especially the subset of "Evangelical Christians") as counter-cultists. No wonder there is so much misunderstanding!
I've since learned to become much more fair-minded. In the meantime, my own faith has been strengthened. Nothing has been compromised; much has been gained. That is the biggest reward here--my own faith has been strengthened. This is why I suppose I can say I have a "testimony" of respectful interfaith dialogue, as opposed to simply putting up walls and engaging in antagonistic debate. (For the record, I do believe there is an appropriate place for healthy "debate", but I see a difference between informed and respectful debate on the one hand and misinformed, open antagonism in pseudo-debate form on the other).
Frankly, one of the biggest obstacles in all of this is that sometimes what is understood by what we say isn't exactly what we mean, since we use different theological vocabularies. Seeking out mutual understanding through interfaith dialogue has, for me, been a step toward becoming theologically "bilingual".