I purchased the BES 2150 instead of the BES 2100 primarily because it has a backlight in the display. I assumed the performance would be the same for both units since they appear to be identical from all outward appearances. After I started using it, I discovered that every shortcoming of the BES 2100 that had been articulated in the reviews on this site have been resolved in this new model. This translator is perfect in every way starting with the size and the outward appearance. The case is very high quality and very stylish. The size is just perfect, both for portability and for the size of the keyboard and display. I also found this unit to be very easy to use, quite contrary to some of the reviews of the 2100. Also, there seems to be no appreciable lag between the time you press the enter key and the time the response shows up on the screen. In particular, moving through the conjugations is almost instantaneous, which was one of the slowest features of the DBE 1450 which would take, literally, several seconds to move from one verb tense form to the next. The 2150 moves between these conjugations nearly instantaneously. And, you can pretty much respond to all the shortcomings that have been articulated about the 2100 with the phrase, "the 2150 fixes that." As an example, someone stated that you had to go through some circuitous path to get the 2100 to speak the sample phrases that come up when you look up a particular word. Well, apparently, the 2150 fixes that because all I had to do was to highlight the particular phrase and hit the speak button, and voila, it says the phrase. In short, this is a high quality, powerful tool and I would highly recommend it to anyone who needs the power this translator offers. Not everyone needs, or wants to pay for, that level of performance and sophication. This translator is a bit expensive.