Thus far, I haven't had any issues running Native Instruments Essential Bass. It has always run smoothly within my configuration, which consists of a Mac Book Pro that has a 2.2 Ghz Intel Core 2 Duo processor and 4 GB of RAM. I run the software in either Logic or MOTU Digital Performer depending on what I want to use it for. I can't exactly quantify the performance that I am getting, but suffice it to say that as long as you have a adequate system to run your software on, I don't think that you will have any trouble running this.
Overall, the Native Instruments Essential Bass is a very powerful piece of software. It gives you access to just about every type of bass sound that you can think of, including electric and upright basses. The sound are quite realistic and I would imagine that they are sampled from top notch tones. The price is reasonable as once you have it you will be able to get just about any bass sound that the virtual world has to offer. If you are looking for virtual bass instrument software, the Native Instruments Essential Bass is the way to go.