I'm actually surprised Freeport is the top visited town in Maine. I would have just assumed Portland or Bar Harbor (maybe even Camden or Ogunquit). But I guess Freeport's status as a hybrid town/ outlet mall would make it a year-round destination (I know buses go up from MA all year round) whereas Portland and Bar Harbor would see stronger fluctuations in visitors with the seasons.
I don't know if I'd go so far as to call those things anti-urban. Bellevue Avenue (where most of the mansions are centered) is not necessarily "urban" because the houses (estates, really) take up so much square footage and have well manicured lawns, etc. However, it's not anti-urban either. It's merely a few blocks from the city center, it's walkable (part of the draw of the mansions is that they're all spaced out in city blocks within walking distance from each other). Bellevue Ave. is a wealthy streetcar suburb on steroids in that you have single family homes within a typical urban grid that are all close to the core of the city. Not unlike the Western Promenade in Portland's West End or the houses along the Jamaicaway near Jamaica Pond in Boston. The caveat is that the homes in Newport are MUCH larger. Still, at worst it's suburban and it's the kind of suburban that we all appreciate in cities.
The Cliff Walk isn't urban because it's a natural feature, but given the proximity to downtown Newport, I'd say it's something akin to a great city park which is essentially urban. Public spaces are part of any city's urban appeal and the Cliff Walk is part of Newport's. I'd throw it in the same category as the Eastern and Western Promenade in Portland, Emerald Necklace in Boston (outside of Central Bosoton), or the Presidio in San Francisco. It's not a central urban park, but it's a great natural feature in an urban environment.
The Tennis Hall of Fame is easily the most urban of the bunch. It's a museum/arena cluster in an urban part of town. In fact, The exterior of the THoF is retail and dining space coming right up to the sidewalk (
google maps). I don't see how it's any different from a place like Fenway Park except that it draws people in on a regular basis (because of the museum) instead of just sporting/concert events.
We're definitely on the same page re: Market Square in Portsmouth. I don't know if it's my favorite urban space in New England (I've always had a soft spot for
North Square in Boston), but I'd say it's better than any one spot in Newport, Portland, or Burlington too. That said, I think you'd find similar urban vibrancy on Thames Street in downtown Newport and maybe even more so on Bannister's Wharf (easily one of my top 5 urban spots in New England). Still, The cohesiveness of downtown Portsmouth, in my mind, beats the others.
I'd also say that Spring Street (take a virtual stroll on google maps) and the intersecting streets remind me a lot of Portsmouth's Strawberry Bank and Washington Square and Trinity Park are as good as any central urban park anywhere.
Out of Portland, Portsmouth, Newport and Burlington, I'd say that Portland easily has the best restaurant scene of the bunch. I don't know which I'd give 2nd place to because I haven't dine in Burlington or Portsmouth enough to compare to NPT. For nightlife, it's got to be Newport for me. But again, I've only gone out extensively in Newport and Portland of that bunch (last time I went out in Portsmouth, you could smoke in bars). Newport has a great collection of bars downtown and just beyond(more than most cities 3x its size). Many of them are right on the water. One of my favorite Irish Pubs anywhere (Buskers) is in Newport. And while Newport's bar scene is clustered together so you can really walk to any of them, you get different atmospheres depending on which direction you go. Downtown bars are typically a little more "yuppy" (with some exceptions) while Lower Thames (South of Memorial blvd) has a more local scene. Broadway, just north of Washington Square has much more of that granola, artsy vibe. I'd also give the edge to Newport for shopping too since it has a large representation of both local and national brands. More so than the other three.
If we're talking simply attractive to tourists, I'd probably go like this:
1) Boston/Cambridge
2) Portland area (inc. Freeport, Cape Elizabeth, etc)
3) Newport
4) Burlington
5) Portsmouth
Now, if we're using this criteria
"there has to be some combination of the urban dynamism that attracts tourists (not to mention students and retirees), along with employment centers, urban amenities, livable and walkable neighborhoods, and so on.", my list would be as follows:
1)Boston/Cambridge (easy)
2) Providence- enough merit to make it a great city on its own, but proximity to Boston is a huge bonus
3)New Haven- a lot of people discount CT, but New Haven is very much a New England that happens to be on major transit corridors- I-95, Amtrak, Metro North, I-91, etc.
4)Portsmouth- On its own, Portland would get the edge in my opinion. But Portsmouth has a lot going for it independently with the added bonus that it's a reasonable commute to Boston from Portsmouth.
5) I'd put Portland or Stamford here. Stamford has a lot of shopping/dining downtown, it's on the coast and it's on a great transit corridor (easy access to NYC). It's main drawback is that the downtown area really lacks the same sense of place that Portland offers. It's about as generic a New England city as you'll find. However, there are those that write Stamford off as a New York suburb that just happens to be within New England's boundaries and they have a good argument (though I'd still argue that New Haven is very much a New England city). If Stamford doesn't count, Portland gets my #5 spot.
Hopefully someone with almost equal experience in all four can weigh in.