Yes, Ableton Live and EnergyXT are much more like what I'm used to, but like ACID, they're not free. They're professional software.
I don't know the aspects in which each one gains ground on the others and/or falls flat, but here's what I do know:
They all have lame demo versions. Just judging from the feature lists, EnergyXT's demo is the worst, followed by ACID XPress. While Ableton Live Lite is the only one that can save, it's limited to four MIDI tracks - a lot less than I'm used to. Truthfully, my music doesn't usually have more than 4 instruments playing concurrently, but I do often introduce and remove instruments throughout the piece, so I would have to use Program Changes often if I were limited to 4 tracks.
Unfortunately, that'll make it a choice between using my favorite VSTi (limited to 4 instruments) or having more than 4 instruments (using the crappy standard GS WaveTable synth). You see, my favorite VSTi synth ignores Program Change events, so I need separate tracks for each instrument I use.
Still, I'll consider Ableton Lite. I'm actually finding Temper difficult to use. It's annoying with the snaps. Like with many programs, you can override grid snap with the Alt key... but once you do, the snap becomes relative to its current position, and the only way to get the note back onto the grid is to quantize it. Also, sometimes playback completely stops being voiced and I can't get any sound until I reboot the laptop.
About LMMS... I don't know what to say. It just doesn't fit my niche. While it made some cool stuff, it felt like I wasn't truly in control; everything seemed to revolve around sound files and sound plugins. A lot could be done with these elements, but in the end I felt like it all boiled down to me giving the computer direction on when I want stuff to play, and then having the computer make music. The reason I felt that way is probably because LMMS isn't consistent with the way I like to write music. I enjoy working with MIDI specifically because, by the nature of its structure and use, it is consistent with how I write music. LMMS has MIDI, but it starts to get unwieldy when you try to write a whole multi-track song with it. Clearly, it's not intended to be used that way.
Everybody says that "LMMS can do anything," but I don't know. From what I've seen, LMMS can't do everything for everyone. But it certainly is complete in its purpose, and it seems that it can easily create any sort of music assuming that it fits your style of writing music.
In any case... FLAME SHIELD, ACTIVATE!
EDIT: Uh, I can't find any downloads anywhere for Ableton Live Lite. As far as I can tell from Google searches, Ableton used to offer it on their site (not anymore; now they just have a 30-day limited trial of Live), and it also used to come preinstalled on some computers.