The AT 2020 is the one and only mic that can do what it does.The reviews from pro recording engineers have all given it 5 stars
the AT4040 a little more has a larger diaphragm and was used to record a U2 CD, the mic AT 2020 is now being purchases in bulk standard orders of 10 per studio, as the SPL level for a condenser is mind blowing and S/N is off the charts it beats many mics that cost 500.00 or more. I own several and I have a music biz and am a pro recording engineer and producer and recording artist.
as all engineers know the shure Sm57 was and still is the ultimate work horse mic and every studio has many of them, however when using a few or several sm 57's you get into problems, you can fix it if you know how to get in and do a small soldering Job, the AT 2020 is quickly out doing the sm57 the bulk studio sales say it all it is now the new multi task work horse.and for a MSRP of 99.00 you simply can not go wrong.I highly say go with it and you will be happy with all it can do as well as lay down excellent vox tracts so go get it.The MXL mikes are hot but nowhere as good, not even close, the M-audio Nova a 100.00 mick is nice, but a tad fragile and not for multi tasking and is M-audios intro level vox mic.
The At2020 also has a new product that is connected to your USB port around 130-150.00 so do you want to record direct to a PC you may consider the new USB AT 2020, but if you will be using it for many applications go with the standard AT2020.
hope this helped.