I use the original MGT-4 with my Rumble Stage 800 playing live and in my home studio. I was intrigued by the GTX-7 when it was introduced, but have not been sufficiently enticed to buy it.
Regarding advantages of the GTX-7, I think there are 4 main differences to note:
5 directly selectable presets:
This is the most obvious difference. You can switch easily among 5 presets without having to bank up and down. If you do a lot of preset changes during a song, this may be a significant benefit to you.
I tend to use one preset for any given song. I have the 3 most-used presets (clean, vintage, distortion) saved to my Favorites setlist, and use the Quick Access function on the MGT-4 to switch among them. The GTX-7 does not appear to have the QA feature. Beyond those 3 presets, I tend to dial-up the preset I want using the encoder knob. Since my amp is either stacked on top of the extension cab, or on an amp stand, it is easily within reach. If not, I can bank up and down with the MGT-4.
Which brings us to...
Separate bank button:
The separate bank button is a "nice to have" feature. On the GTX-7, you click the bank selection foot switch to bank-up, and hold it to bank down, 5 at a time. On the MGT-4, you bank up/down by stepping on the right/left 2 foot switches simultaneously. It works well enough, but I'm sure you know what a pain that method can be; especially if you're switching through several banks, because you're only moving 3 at a time.
Another small thing that makes a difference when trying moving rapidly through banks between songs is, again, the fact the MGT-4 moves in banks of 3. On both units, when you move to a bank, you still need to step on the preset you want within that bank. On the MGT-4, if you are on preset 3, and bank up, you are presented with preset 6; then, if want preset 4, you need to quickly calculate to step on the first button. I know sounds stupid, and maybe it is; but I think the human mind deals more intuitively with sets of 5.
Given the double-switch dance and the little arithmetic quizzes, I usually just dial it in.
More granular control of effects on GTX-7:
This one is going to depend on your preferences and ways-of-working. Both the GTX-4 and MGT-4 give you the ability to enable/disable effects on the basis of effects "category", or by controlling the "first
x" number of effects. Obviously in the latter mode, the GTX-7 can control the first 5; whereas, the MGT-4 can only control the first 3.
This is a clear advantage for the GTX-7; but, I question whether the mode is really useful, or whether it makes things more difficult to manage. Consider that we are bassists. The number of effects we put into our presets are likely to be fewer than guitarists. In most cases, there would not be more than one of each effect type. But what may change among presets is effect
placement. Given this, I would suggest that using effects control in "category" mode would be superior because we don't need to remember which effect is where in the signal path; rather, just that the buttons control (for example) 1: Stomp, 2: Mod, 3: Delay. In this mode, although the GTX-7 still has more granularity, the difference becomes less significant.
And finally...
Improved looper control:
I am not very big into looping, but having each of the looper controls on a separate button is a tremendous advantage. If you are into looping, I would think that this feature alone would be worth the price of the foot switch.
So, my bottom line recommendation:
If you purchase the Rumble Studio 40, which does not include a foot switch, purchase the GTX-7. For the minimal price difference between the two, "Buy once, cry once."
If you purchase the Rumble Stage 800, which includes the MGT-4, use it for a while and see what you think. I can see why guitarists would want the more granular control the GTX-7 offers. For bassists, I think the MGT-4 is very functional. I still have no intent of getting the GTX-7 at this time, even having outlined its clear advantages.
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