I thought 5/3/1 was a great program. I like the short cycle lengths. All the good lifting principles are in there (eg. sub-max lifting, decent frequency [2+ times /week per muscle group], focus on major compounds, progress load over time, deload, goal/PR oriented) and Mr. Wendler spells things out clearly enough that pretty much any lifter wanting to get bigger and stronger has a good chance of success. It's quite like a 'simplify & win' routine but with emphasis placed on going all-out on just one major compound each session (still avoiding failure, but as big Jim says, "it should take some life out of you!"
![Wink ;) ;)](https://cdn.jsdelivr.net/joypixels/assets/8.0/png/unicode/64/1f609.png)
and then, depending on your lifting goals, adding in assorted higher-rep accessory work as desired (there's good advice on this too).
There's plenty of helpful advice included on the 'big four' along with a range of accessory lifts along with ready-made templates to work from if you don't want to create your own. Add to that that it's written with a good dose of humour (well, it made me laugh) and you have a worthwhile purchase.
Personally, I don't think you're likely to make better gains in size and/or strength with 5/3/1 over a well planned out HST cycle, esp. if you go to triples or negatives for some strength work at the end of your HST cycle. However, 5/3/1's shorter cycle lengths can often be a useful way to schedule your training over the course of a busy year and the general change in set-up can be be very refreshing, so it gets a big thumbs up from me. I'll definitely be going back to it from time to time.