Mechie thanks a lot for your interest!
In very short: i think one is able to learn both and either version will work very nicely - i had a LH variant early on and now use a RH variant - in my opinion there’s not too much difference.
For me, more important than the LH/RH variant decision is the placement of the SEQ v4+ close to your main keyboard rig, so you have minimum travel times with your hands, i.e. when you record a sequence with the main keys and reach back to the SEQ v4+ - this time should be minimized. It is similar for the MatriX, it is recommended to put the MatriX close to the v4+ to reduce hand travel times, because you’ll sometimes want to “jump” between both units at a time.
That being said, if you’re only using a SEQ v4+ right now, some people have argued that for right-handed players a LH might be a bit better, as the transport controls are on the left and you can use your right/better hand to control the SEQ v4+ main mechanical keys and use your left hand for the jog/mode/transport section. But: i cannot confirm that 🙂 - i use the RH variant as a right handed person and find myself controlling the SEQ v4+ with the left hand a lot of the time, while playing simple sequences on the keys with the right hand, it works equally well.
So: the difference probably isn’t really that big, i’d recommend to choose what you like better visually. It’s also interesting, after more than 3 years of SEQ v4+ sales, we have an even 50:50 ratio of sales on both units, three years ago, i would have bet one variant would sell better, but that is not so 🙂.