The Series 5 is a re-design of Braun's popular 360 Complete. It uses the same cutter, so the shave is the same as the 360. The differences are in the overall shape - Braun has done a great job with the re-design. The shaver is easier to grip and has the same basic form factor as the top of the line Braun Series 7 (Pulsonic). Unlike the 360 Compete, the Series 5 is washable under the tap. It's NOT submersible or a wet shaver, but you can safely use water to clean it.
This model lacks the pulsating action of the Pulsonic, but don't let that stop you from buying it. I've used the Pulsonic and, on my face, the Series 5 does as good of a job in most spots, and a wee bit better on the neck. I also find the "push up" format for the sideburn trimmer to be better/easier to use than the "flip out" format on the Pulsonic.
The best part of any Braun shaver is the cleaning system. In a word, it's perfect - no other cleaning system comes close. Works well, and leaves the shaver spotless and lemony-fresh. The down side, of course, is that you need to purchase refill cartridges. If you clean every day, expect about 4 weeks per cartridge. I get mine to last about 4-5 months by cleaning once a week using the cleaning base, and cleaning the rest of the time with water. You have to remove the cartridge and re-cap it so you don't lose solution via evaporation.
Neat trick for quick cleaning - just click the head release button but don't remove the head. Then turn on the razor and let the stubble fall out. Gets about 75% of the whiskers out in about 2 seconds. Safe for the razor - the tip is in the user's manual.
The Series 5 comes in two models (760 and 790) - the only difference is the number of lights to show you the battery charge, so look for whichever is on sale. It also comes without a cleaning base (the "cc" models have the cleaning system, those without the "cc" in the model do not).
If you favor a gentle shave over a ultra close shave, the Braun is for you. While I like the shave from the Series 5 (more so than the shave from the Pulsonic), I have to say that I prefer the shave from the Norelco Arcitec - it's a rotary shaver, but still quite comfortable, and excels at getting those pesky neck hairs. My absolute favorite foil shaver is the Panasonic Arc IV - 90% as comfortable as a Braun, but closer and faster. Check all of them out - all are great shavers with unique features.