Since you are asking this question I will suggest the one you have is more than adequate. Consider what you will be using it for. I use mine for finding programming problems related to an output. Or PWM output signals, or I2C signals or RS232 signals.
None of these would require anything more than you have.
I will note that the one you have, has no internal memory so you are limited by the USB bus speed. The specs don't state the USB speed so I would assume USB 2.0.
I've have one very similar to this one and have not run into any limit of the analyzer on any of my projects. Probably the more important thing is the software, it can be a breeze or make you hate having to use the analyzer.