CrackBerry Genius of Geniuses
This was probably the only complaint I had when testing the Z10 at BEF recently. It's not just the small size, but there's not enough contrast between the color of the suggested word and the fret bar behind it. I use the predictive text on the PB and love it, but it is a disjointed typing experience. Seeing the online videos, it didn't seem like an issue until I had it in person. I asked the rep if there was a way to change it and he spent quite a while looking for a way without success. Hopefully, they will add some color or sizing options in the future.
As for the other suggested solution, I will admit that I probably do need some reading glasses as I am hitting the age where eyesight begins to deteriorate. But a big portion of BlackBerry's userbase is also nearing or past the same point, so I'm not sure it's the best overall solution. Nor would it be good for marketing...
Landscape made it slightly better. It should be fine on the PlayBook.