4EXT is a touch-based themeable recovery with a lot of new features and two different control (Android mode) versions, free and paid. It requires a CDMA or GSM HTC EVO 3D in either S-OFF (revolutionary) or HBOOT unlocked (HTCdev) states.
The free version is a fully functioning themeable recovery with the same functionality, and limitations, the other recoveries have. Some of the neat features about it, other than not having to press the power or volume buttons, are the haptic feedback and the auto naming of the backup based on the ROM you're currently running (which you can disable in the 4EXT recovery settings if you don't like it).
The paid version ($2.64), which you can preview for three days, adds the extra features of Recovery Control, an application that runs in Android mode and allows things such as checking md5sums before attempting to flash via recovery, calculating whether you have enough space to make a backup before attempting, queuing up multiple zips for installation, and updating your recovery (if you want it to) within 5 minutes when there's a new version. The list is pretty darn long.
4EXT installs are the easiest I've run across. You install the recovery updater APK, it tells you what phone you have, downloads the appropriate recovery, and flashes it for you. Backups appear to be made in a ClockworkMod-compatible format, as they're saved in /sdcard/clockworkmod/backup/date_and_rom_name/.
If you're on HBOOT 1.50 S-ON, you'll be wondering where you can grab a copy of the recovery image in case you want to flash a kernel via Fastboot. As far as I can tell, every backup you make will store a recovery.img of the recovery along with the backup. Although some people say it's dropping a copy of recovery in the root of the SD card, that has not been my experience.
One of the features I dig in the application's flash zip menu is the ability to hide useless directories. This scans your SD card for all flashable items and just displays those. No more scrolling through a page or two of directories looking for the lower case "download" directory, not to be confused with the upper case Downloads directory some other application made. Just all the zips are presented for you.
As for backup speed, it appears to take as long as most recoveries that do not use compression. People coming from TWRP 2.0 are going to notice immediately larger and longer backups – larger due to no compression, longer due to the SD card writes being the limiting factor.
It appears to back up the APKs in the data.ext4.tar file. Coming from a couple of recoveries that ask whether or not I want to back up .android_secure, this was a bit of a change for me. If you want smaller downloads, uncheck the backing up of data.
This recovery feels solid and well designed. The only thing I'd really like to see available for download is a flashable zip or a fastbootable image just to have online in case the phone is unable to boot into recovery or Android mode (and perhaps I just can't find it). It's a little difficult to recover from a disaster if you don't have the image file it creates laying around on the computer you're on. But, it's not a big deal. The devs went for a computerless install experience, and that is quite a feat in itself.
If you're looking for a new recovery to play with, this one's really, really sweet. However, as it's only been out since around Friday for the EVO 3D, you might want to hang back and see if people have issues with it. For what it's worth, there are no real complaints so far for me.