I will grant that most boas are better feeders than ball pythons, though I do have one Solomon Island ground boa that puts that theory to the test.
Ball pythons are known for going on fasting periods, much to the dismay of their owners, while 'most' boas do not - never a guaranty with wild caught or some neonate animals. My bp has gone for fasts lasting several months. At first it was completely nerve wracking and I thought I'd lose it. Eventually I got used to the somewhat annual phenomenon and just go with the tide. All in all, I love my ball python as much as any of the boas in my collection. They are great pets IMO, generally with good dispositions and they don't get terribly large. A great boid all around. As Hoppy mentioned, you'll need to be careful of the many bp 'morphs' out there as many are not legitimate and the return isn't immediate due to the low clutch size.
There are a number of snakes in my collection (listed below) and all of them have been great pets and I've learned a good deal from each type. For small boas, my obvious first choice is one of the Candoia (Solomon Island/Santa Isabel ground boas or Viper boas). The different rainbow boas are also great. My Colombian rainbow was a rescue and, despite horrid treatment from his previous owner, is a gentle docile snake that turned into quite a beauty. There are a few insular forms of the Bci (Hog Islands probably being the most widely known) as well as a number of other smaller boas (Bannana boas, rosy boas, rubber boas, to name a few just off the top of my head). I am partial to the Colombian redtails (aka common boas) even though they reach lengths up to and exceeding 7 feet - most of my collection of Bci is in the 7' range with the exception of 3 juveniles. There are also some great smaller pythons. The childrens and spotted pythons are two of the first small pythons that come to mind, both great snakes (don't know if they interest you or not though). Basically there's something in this hobby for everyone. 
Raven
5.3 Bci - Colombian Redtails
1.1 Dumerils boas
1.1 Solomon Island ground boa (Candoia carinata paulsoni)
0.1 Santa Isabel ground boa (Candoia carinata paulsoni - white phase)
1.0 Colombian Rainbow boa
0.1 Albino Burmese Python
1.0 Ball Python
0.1 Queensland (coastal) carpet python
1.0 Jungle X Coastal Carpet python
0.1 Jungle Carpet X Diamond python
1.1 Normal Phase Corn Snakes
1.0 Snow Corn