9/22/18 Update
Before I start, the Helix gets easier and easier to tweak very quickly with each use. If I was to need and an EQ in my chain, cuz the sound guy wants me to cut lows, or I want more highs, that is easily done in seconds, and I can store it somewhere else so I don't have to mess with my painstakingly created patch that sounds good somewhere else, and I can compare the two patches later. Distortion too loud? Just get in and change it as quick as any gear you are already familiar with. There is a learning curve, and experimentation, but it can do whatever you want. I also found that you don't have to do things like you do in the real world. Where yu put things makes a huge difference, and some thing that are not intuitive, work pretty well.
Purchased and returned a QSCK12.2. It was an AWESOME speaker. Caveat, I play in a really loud band, with a really loud drummer (I know, it isn't healthy!). So I am looking for serious volume and punch. If you want the QSC only for the loudest home recording monitor in the world or "quiet" stage volumes, again, AWESOME. I also tried ALTO's in the store, but while they are not as expensive, they don't match the QSC. I don't think they were the 315's, maybe the 215's. QSC was better, and yeah costs twice as much. Bottom line, and in my opinion only, there doesn't seem to be a substitute for moving air and headroom. Also, while money has only been a secondary or third consideration behind sound and weight, those are the three things I am considering. My Mark bass tube 800 sounds killer with the ME50B. I usually run two 4x10 cabs, but I can get the job done with one cab. So that is basically my benchmark. I don't get to use all the effects I would like to with the helix. To be clear, I am running the ME50B at 10 and 2 with the DBX compressor model and all eq settngs at 12 o' clock. I have the Mark set at 8 o'clock on the pre and master gain between 10 and 12 o'clock. Really musical, crisp and clear, and LOUD. Again, benchmarking. So this rig is relatively light, but it is still requires more than a car to move, as even a single cab is large. So here I am considering my Helix stage volume dilemma....The helix does not sound as good in front of the Mark rig, and it weighs more and takes more space than the ME 50 B. Also, I keep meeting guys that love the Boss bass stuff, which I believe is really Roland, and would explain the quality sound there. I would add here that I have the newer Boss bass pedal that costs only 200 bucks, and if you are on a tight budget, it is pretty cool, but the lights are annoyingly BRIGHT, and it is TINY. It also does not sound as good in front of my mark rig as the ME50B. Next up, the quilter Bass Block. I is not as loud as the Mark Tube 800. I bought it as a back-up after one of my Mark heads caught on fire. It was my first head, and after 5 years of gigging it BURNED. I had to call the fire department burned; a big disappointment. So I have another, newer, mark tube 800 head, and that is what I used last night, and I bring the Quilter as back up. Now, the Quliter, using the XLR in, and turned up all the way, with the Helix in front of it and the output near 2 o'clock, is almost as loud, and I think is gonna get the job done, and meet my really loud live sound requirement, without adding additional weight , and without really losing any weight, but gaining on sound as I can use the Helix effects (I LOVE the Obsidian), and of curse you can just run a whole different rig to the front of house at the same time, and have a different setting for each song, which I do for my other cover band. So, I will be posting about my success or failure with the Quilter in the live situation, but I love the way it sounds so far. I am going to run the amp at max power and use the Helix for my volumes. Hopefully, the amp will handle it. If it does, I will consider getting a second one and moving away from the wonderful, but heavier, mark tube 800 head, and perhaps even go to smaller cabs. I hope this answers questions for somebody, and I will be back after more experimenting and the next live trial in November.