For Junior high teachers intereseted in simple, easy-to-use probeware solutions, you might want to consider the middle school bundles offered by Pasco.
I have tested two of the bundles "Noodling With Newton" - which consists of what you see above, a USB link, motion sensor and force sensor - and also the "Measuring Matters" bundle - which consists of a pH sensor, heart rate sensor, temperature sensor and USB link.
Right off the top, I'd like to say these bundles get top marks for ease of use - the USB link plugs into the USB port of your Mac or PC. The huge advantage of the USB link and sensors for middle school is when a student plugs in a sensor into the link, the software immediately recognizes what has been plugged in, and brings up the appropriate measuring screen. There's really no need for software configuration, which is a huge time saver for the teacher. So that means setting up to record data consists of plugging in the sensor, and pressing "start". Cool.
Speaking of software, the bundles come with "EZScreens" included - they are screens with very easy to read scales and simple buttons aimed at junior high students. For example, here's an EZ screen for heart rate:
The heart is actually animated, beating in tune with your own heart beat - very neat. Pasco is also including "DataStudio Lite" software, so you can now view your data with the more powerful suite of data analysis tools, simply by clicking the exit to DataStudio button.
All the bundles (there is a "Wondering about Waves" bundle too) are available with accessory kits and teacher guides, which provide extra tools for your experiments, and also a binder of experiments for you to try. The binders come with blackline masters for students, and all the nerdy stuff like assessment suggestions.
Prices are fluctuating these days, so I'm going to bite my tongue before quoting any prices, only to have them change days later! If you are interested in these bundles, I strongly suggest US teachers contact Pasco and have them send you a catalog and price list. In Canada, contact Merlan.
While you're looking at the catalog, be sure to check out the new Xplorer, which allows you collect data remotely, without a connection to the computer.
Have fun with your new sensors!