What this coin looks like (obverse, reverse, mint mark location, special features, etc.): There are 5 major varieties of the 1829 Capped Bust Dime. 4 of them deal with different sizes of the "10 C." on the reverse of the coin. The Small "10 C." variety has nearly the same size letters and numbers as the Medium "10 C." but the "0" is smaller and will not line up with the top of the "1" like it does in the Medium version. The Large and Extra Large versions have larger lettering with the Extra Large having even larger sizes. Although the Large version will have a "fatter" dot in the "10 C." than the Extra-Large variety. The example image above shows the differences and comparisons between all of these varieties. Note the various types of spacing and locations of the characters as well.
The other variety is extremely rare and valuable. The 1829 Curl Base 2 capped bust dime features a curled based on the "2" in the 1829 date. Typically the base or bottom of the "2" is flat and square except in very rare cases. The difference between the 1829 Square Base 2 vs Curl Base 2 is depicted in the example image below: