Sized about the same as a baseball, the firmness was more like a softball. The inside flesh while crisp is not as crunchy as the traditional variety and the skin is much softer (though that may be due to my familiarity to more of a industrial cucumber product).
There was no bitterness, it has a very slightly sweet flavor - but so do green cucumbers that have not been deprived of water when growing. It has a nicely mellow aftertaste, and a slightly higher acidity - but it does not taste like lemons. I would say that the seeds were a little tougher, I would probably remove them if using this in a dish. Burpless? Time will tell.
Concerned that perhaps I'd waited too long to harvest, I decided to pick another (younger) lemon cucumber. No, while slightly crunchier, it had less flesh and less flavor, so the larger one seemed to be at the peak.
So while I'd like to say we'll be featuring these at the restaurant, we may have to wait until a few more blooms decide to fruit - these were the only two I had on my plant. Hopefully I'll have a few more in the next month.