I have been using the Unique Learning Systems (free) Summer Curriculum with my life skills middle school class and we have been enjoying it immensely. I love the automatic differentiation of materials (although convincing students who can write to do so when others are cutting and pasting their answers proved to be a bit of a stumbling block at first). The students like the topics and the extension opportunities that have been created just for them.
I do have some worries about using the curriculum this coming school year with students who have more significant disabilities. Quite a bit of adaptation is still going to need to be done, inspite of the different levels of the curriculum. Some of these adaptations will need to be done no matter what curriculum is used, such as finding or creating object symbols, adapting materials for learners with low vision and using adaptive tools (i.e. switch scissors) to finish the work. Some of the curriculum will never work for learners with severe physical challenges for example most of cooking activties contain ingredients which are swallowing hazards. However, hopefully as more people begin using Unique they will share customized materials on Adapted Learning and other sharing sites.
One tip I have is to use the Firefox extension Down Them All to download the PDF files in the curriculum. Down Them All allows you to check off all the PDF and then have them all download at once, saving quite a bit of time. Hopefully Unique will at some point allow us to download entire units at a time, but until then Down Them All is a good solution.