The JMT maps have been completely brought into the 21st century. They are free, but they require a log in.
The last update was over 3 years ago and they were still using the old scanned topo maps that others use. This set is built from the ground up like all the other postholer maps. So, if you want to see and compare in very high defintion take a look. They can be found here:
http://postholer.com/mapbooks/preview.php?trail_id=4
There are four sets in PDF. 2 different scales and northbound, southbound. The scales are 1:63K (1 mile per inch) and 1:30K (half mile per inch). 12 pages and 28 pages. In my opinion the 1:63K scale are overview maps. Land feature names, terrain and trail trace detail is lost at this resolution. Yet, that scale is the most popular among the commercial maps such as NatGeo and Tom Harrisons JMT maps sets. It is cost effective, which is probably why.
Near Yosimite Valley
-postholer