The HTC One S is a really difficult phone to judge. On the one hand its plasma-etched and super-slim design, fast processor, decent screen and good camera all add up to make this a major improvement over top phones of last year and certainly competitive with many current handsets. But, on the other hand, that plasma finish may not be as tough as first thought, it only packs 16GB of storage and the AMOLED screen is far from perfect.
Ultimately, the only compelling reason to get this phone rather than the HTC One X (more storage, much better screen) is the slightly smaller screen on this handset. The One X's 4.7in frame is pretty large so the 4.3in One S is noticeably easier to grasp. But, it's not like the One S is exactly small anyway, so we'd still go for the bigger of the two.