I spent some time with the new Amplitube ENGL models today, comparing them against UAD's 646VS model which I've enjoyed for a while.
There's a common character to these amp sims, to my ears. They all sound good, with AT's models perhaps having a bit more bite at times. While trying various settings, I sometimes preferred UAD, sometimes Amplitube. You can't go wrong with any of these, really. All have a wide range of applications, from clean to crunchy. I thought AT's Powerball model sounded close to the UAD in high-gain mode, while the 650 was closer to the UAD's clean sounds.
The UAD model does seem to have a smoothed-out character compared with AT's. Less "in your face." I think this is a common characteristic of Brainworx's stuff, which can be adjusted by using additional plugs like transient shapers or saturation.
Now, comparing these two AT ENGL amps to other AT models, I found I preferred their Hiwatt model ("Hiamp") over the ENGLs most of the time. Just sounded better to me overall, including the cab, which I liked better with various amps than the new ENGL cabs. YMMV, of course.
So I doubt I'll be buying these new ENGLs, as I think I'm covered for this kind of sound. Plus, I like using UAD's amp when I can, as Amplitube is a CPU hog. Still, good stuff from IK.
Cheers,
Eddie