First of all Yuppicide thanks for the post & for coming out from Jersey for the show. Also a big disclaimer that Hot Diggity is a client of mine so obviously I'm not unbiased. Oh also thanks Foodbme for the posting the link..
Really I think that "gourmet" (eclectic?) hot dog places like Hot Diggity are not really in the same category as traditional hot dog joints. They're aimed at different customers and are going for different things.
That said HD definitely uses better dogs than most in Philadelphia, it's hard to find ANY natural casing dogs here. Most places look at you like you're crazy for even asking, they just grab whatever skinless nameless dog is on sale at restaurant depot.
And if you're going to eat a hot dog loaded with ridiculous toppings, HD is the place to do it. A lot of these "eclectic" places just load the dogs with whatever. Keith (owner/chef of HD) is a former fine dining chef and everything is made from scratch, and really really good.
I also agree on the big rolls. Every single new hot dog place that opens in Philadelphia serves their dogs on giant hoagie rolls. Can't stand it. But hey at least at HD the bread is good (Liscio's Bakery) and fresh every day. Not every place does that.
If you want to try something more traditional, check out out the "Detroit Coney" special they're doing this month. It's Detroit - style chili made with organic beef hearts that they grind themselves. It's a lot dryer than Detroit Chili, actually reminded me of Flint, but the flavor was there. Also they trim the roll down to more hot-dog size.
Or for a hot dog that's really about the hot dog, come to Philly this summer and check out Scott Dogs. It's a cart from the chef of the South Philly Taproom, and they really make their own hot dogs. Traditional, short and stout (sort of like a Zwiegle's) smoked beef and pork dogs, steamed and then finished off on a flat grill contraption. Also on Holly's Site.