I've been using the TextBlade pretty consistently for nearly a month now.
Going back to a standard keyboard is not difficult, however, it is frustrating for me. I find the frustration is as @orand and @brotherlea have stated, there is a frustration because of how far the fingers have to move when typing on a standard keyboard. I feel clumsy and slow at typing on the regular keyboard and there is an interesting cognitive effect in that I find I have to keep retracing my thoughts to get them recorded.
I also have moments where my fingers seem to spaz. I'll be typing and I start making errors and then suddenly everything I'm typing on the (standard) keyboard is complete gibberish. I suspect this is because of the muscle memory that has developed around typing on the TextBlade.
But if I slow down and make the typing more of a deliberate action rather than an automatic action, I'm fine.
I have one computer I have to use into which I cannot plug a Bluetooth dongle. I have caught myself sighing when I have to make use of that computer. It's a stupid reaction to having to use a regular keyboard, but it is also very real.
But, no... there's no real, problematical issue with switching back and forth. You may not like having to use a regular keyboard after using a TextBlade, but I strongly suspect you won't have any significant issues doing so.