I had a Standard pretty much from when they were first released, and now I use an Axe-FX II.
The amp and cab modeling in the II is a substantial improvement over the Standard, in my opinion, particularly for sounds that are not massively driven. Even heavily driven sounds are better in the II, but the Standard gives a huge "wall of sound" that is more difficult to replicate in the II, even if it's a more "artificial" sound. That said, you can get some great sounds of all types out of the Standard if you are willing to spend time tweaking the advanced parameters. However, tweaking carefully will get you sounds in the II that are unbelievably good. With some of the better third-party IRs, like Ownhammer, it's getting to the point where a good programmer can make sounds that are tough to distinguish from a well-recorded real amp in a mix.
In terms of recording, the AFX2 also functions as a soundcard, and it has USB in and out, so you don't have to deal with all that MIDI-to-USB conversion crap anymore like you do on the Standard. I am using the AFX2 as my DAW I/O for now, and it seems to work fine. Obviously, it wouldn't be enough if you need lots of analog I/O for vocals, drums etc. The AFX2 also allows you to record both wet and dry tracks simultaneously, so that you can re-amp later, which I think is a great feature.
The AFX2 and the Standard both use the same version of Axe-Edit for editing purposes, though Axe-Edit is currently "down" at the moment--the old version doesn't play well with the current AFX2 firmware, and the new version of Axe-Edit has been delayed in development.
If you're not in a rush, I think you'd be better served to save up and get an AFX2. I recorded seven albums with the Standard and will always have warm feelings for it, but the reality is that the AFX2 is a big improvement.