Bummer about the PCM, I still think giving up PCM is an error by Mpx but there we go. The 4000 has PCM/A mode, but don't let me tempt you into buying one! Ahem, as if I would even try
The 4000's Multimixes allow you to adjust many servos at once, I love being able to adjust the knife edge mix in flight but can't if it is 2 aileron servos on a 3030. I can do it with the 4000.
If past Mpx experience is anything to go by, the manual will not do justice to the radio so I suspect the RE may be a tad better than the manual suggests.
Anyway, I like to fit the type of switch I want, where I want. 2 or 3 position, spring loaded or latching etc. To my 4000 I fitted a push button with a bright red top to operate the timer. That flexibility is gone in the RE.
The push button I fitted for the timer is a push to make, spring loaded, it is not latching. So how does the timer keep running after I have pressed and released the button? The 4000 includes software emulations of switch types which can be allocated to real or software switches, so I allocated a latching switch emulation to the push button and now it behaves like a latching switch even though it is not. I press the button and the timer re-sets and runs. I push it again and it stops, I push it again and it re-sets and runs and so on. I don't think these exist in the RE.
Call me old fashioned but..... I actually prefer holding the wide shallow box of the 3030/4000 to the narrow deep Japanese/Evo box!! I have used digi trims when I regularly test fly other people's models and I really don't like them - the trims that is, not their models! Digi trims are great for administration of a model but bad for use in flight and that is where they are needed most. The 4000 has extensive software for the trims that the 3030 does not have, making the mechanical trims all but as easy to administer and adjust as digi trims, while maintaining the advantages of mechanical trims when flying. Multiplex had to go down this route because digi trims are the fashion and they need to sell the RE, but for me it counts against the RE.
I felt that one of the main limits of the 3030 is that you get just one real software switch, the Gx. The 4000 has stacks of switches, and of many different types, including an analogue type which attenuates over a window rather than binary on/off, and a logical type in which you can combine inputs with AND and OR tests, and several other types. And where the 3030 Gx switch works on a control position, the 4000's switches can be set to control or servo positions - servo position being the result of mixing and/or slowing so is not the same as a control position. These can be built into very powerful controllers because you can allocate several switches, and of different kinds, to one control. I get a feeling from the RE manual that each control only has one switch, of the on/off type, see the screen shot on p94 of the manual. If that is true then it limits what can be done compared to the 4000. The best thing in my 4000 that I will never
give up now is the ability to have the rudder control position switch the elevator rate on and off. It is just the mutt's nuts for automatically swapping from pattern to some 3D manoeuvers and back again without me having to touch a switch. It uses 2 control switches on the rudder fed through a logical switch, and then I attach the rate switch to the logic switch output. If the RE does not have some means of achieving the same end to get full rudder deflection in either direction to control the rate switch, I will lose interest very very fast. That ability alone on the 4000 is the killer application for me.
It transforms an aerobatic flight.
I can attach 2 single point control switches to a proportional retract servo and then use them to switch the door servo for the complete P51 Mustang sequence of door open, gear down, door closed, then door open, gear up, door closed. I doubt that the RE can.
The other main limit of the 3030 is the lack of multi point curves, the 4000 has up to 13 points on all servos. I find a 9 point perfect for the throttle as with trim sensitivity set to 20%, points 1, 2 and 3 match trim back, trim middle and trim forward for setting the perfect cut, ground idle and flight idle. Maybe I am missing it but I only saw 5 point curves on only the throttle control on the RE and that appeared to be heli related. Multi point curves, yes up to 13 points, are useful for matching twin elevator servos to travel precisely together acroos their entire travel.
The 3030 has servo speed control set at the control end. The RE also seems to have it at one end only. The 4000 has it on some controls (will not allow on the 3 primary flight controls for obvious reasons), on all mixer inputs and on all servos. So I set the elevator to have throttle mixed in on my Tomahawk as it tends to nose up quite a bit after power is applied. But there is a delay of a few seconds while speed builds until the strong pitch up begins. Mixing throttle to a bit of down trim would kick in immediately, resulting in an immediate nose down followed by a long nose up. In the 4000 I have the throttle and elevator controls and servos running at normal speed, but the throttle input
into the elevator mixer is slowed so that the trim mix comes in slowly just as the delayed pitch up begins.
Golly, I have rambled on a bit again, but I hope that gives you a deep insight into why the RE is below the 4000 not just in some esoteric theory or features that no-one ever uses, but it translates into hard practice for me.