We encountered 3 major challenges when building Jenny Labaw's umbraco website.
1. The twitter feed on the home page
2. The calendar widget
While numerous calendars exist on the web, we needed a calendar that integrated well with the event system we built. So we built one from scratch ... in xslt. It's rather difficult to create content that repeats a set number of times in a language that doesn't support the for loop. We managed though and in the end we had a calendar that showcased events past and present.
3. The media page lightbox
Setting up a lightbox is simple. Setting up a lightbox that supports the swapping of video, images of any size and multiple lightbox groupings is a tad more difficult. The video transitions were tricky, but they too eventually fell to our persistent research.
This vacation home website has two sliders. The one on the home page is fairly common on the web. It has two arrows for navigation and uses a crossfade for the transition.
The one on the property pages is not nearly so common, for it uses a circular slider. It moves the images in chunks of five and loops seemlessly when the last image is reached. Plus each thumbnail can be clicked to load the full size version of the image into the main display.
Quick and dirty site done in HTML. No framework, no CMS.
SloshPipe Wave was very much a "by the seat of your pants" umbraco development. We started with two comps, one for the home page and one for a generic page. This particular site had a shop page, which is anything but generic.
So we turned to tiny mce templates to allow the user more control over these generic pages. This allowed us to create pre-built pieces of content that the user might not know how to assemble themselves. They could then replace the placeholder content with their own.
This is an asp.net MVC site to promote the city of Seabrook in Washington. People register to take weekly quizzes, to garner points. The one with the most points at the end gets to rent a beach house for a whole year! We integrated social media like Facebook, Twitter, and Google+ so that people can post their results to get extra points. At the close of the content, there have been over 15,000 registered users.
This is the only umbraco site we have worked on that uses a start up kit. While they can be useful for quick development, they unfortunately usually add a more than you really want, which leaves the back end in a bit of a mess. If it creates a large number of page templates for example, the user will be presented with a large number of template options when they go to create pages, which can cause some confusion. Also, since the parentage of doctype in umbraco v4 is set in stone, you have to delete and recreate the doctypes in order to change their inheritance (v5 fixed this).
Overall, I'd only recommend starter kits for people that aren't comfortable writing their own templates and css.
This site was originally in straight-up HTML, but yearly changes to the roster, the coaches and administrators need a way to make changes to the site themselve. As a result, we migrated the site into Wordpress.