Help picking an Apex controller

[habs247]

Thanks Enigma. I have seen that chart but I'm a bit confused about some of the features.

The differences I see between the Lite and the JR are that the former has (correct me if I'm wrong, not sure about any of this):

- ph out of the box with the addition of a probe (to add ph to the junior a pm1 module would be needed)
- a display (a big feature, but smartphone or pc could be used as a workaround)
- vdm (have no idea what it is or if I need it)
- legacy support (again, no idea what it is or if I'll need it given my setup)
- upgradability (a big feature - would I need more than 5 aquabus modules for the equipment I've listed above?)

Does this sound correct? Any insight from anyone on the above would be great. Thanks.