bozman52 wrote:
The a23322 was the standard issue Navitimer for many years. It is no longer being produced, but you can still find them at some ADs. It was replaced by the Navitimer 01. These two pieces are moderately different. The 01 has a 43mm case, so it's slightly larger. However, the biggest difference is that the 01 uses Breitling's new in-house movement. The a23322 uses an ETA movement (the 7750, I believe). Because of this, the Navi 01 is significantly more expensive than the old Navi, but it's also a more desirable watch IMO.
Breitling is no longer making the LE Navi 01, but you may be able to find one still lurking at an AD. The regular production Navi 01 is very similar to the LE, except that the Breitling wings are yellow gold and the date wheel matches the dial color. The LE has white gold wings and a white date wheel. Thus, having the LE version isn't really a huge deal. It won't make the watch worth any more money. However, the LE does have a crystal case back, which allows one to see the movement. This is a really important feature to me, but many don't care about it.
As you mentioned, the World is indeed bigger, at 46mm. It is still in production and should be easy to find. Like the a23322, it uses an ETA-based movement. The biggest difference with the World is that it has a GMT complication. Everyone on this forum is eagerly anticipating the release of a World with the B04 movement (which is the B01 with GMT a complication), but Breitling has not mentioned any such watch.
The World is a pretty big watch, so if you're considering this piece, I'd urge you to go try one on. You should know pretty immediately if you'd feel comfortable wearing it or not. Among these three watches, my personal preference would be the Navi 01, but as you can see from my signature, I may be slightly biased.
Breitling is no longer making the LE Navi 01, but you may be able to find one still lurking at an AD. The regular production Navi 01 is very similar to the LE, except that the Breitling wings are yellow gold and the date wheel matches the dial color. The LE has white gold wings and a white date wheel. Thus, having the LE version isn't really a huge deal. It won't make the watch worth any more money. However, the LE does have a crystal case back, which allows one to see the movement. This is a really important feature to me, but many don't care about it.
As you mentioned, the World is indeed bigger, at 46mm. It is still in production and should be easy to find. Like the a23322, it uses an ETA-based movement. The biggest difference with the World is that it has a GMT complication. Everyone on this forum is eagerly anticipating the release of a World with the B04 movement (which is the B01 with GMT a complication), but Breitling has not mentioned any such watch.
The World is a pretty big watch, so if you're considering this piece, I'd urge you to go try one on. You should know pretty immediately if you'd feel comfortable wearing it or not. Among these three watches, my personal preference would be the Navi 01, but as you can see from my signature, I may be slightly biased.
Couldn't have put it better myself. 
Just one very small point though - the 23322 Navi uses a modified Valjoux 7753, but that's all I would add.