One positive aspect of the case is a 'dry-salt' pad that sits in a removable cage nestled in the foam surround. This absorbs any excess moisture that may have collected on you headphones making them more hygienic and reducing the risk of moisture damage. If you're a regular gym goer, this should be a real boon. That said, I've never had any problems with any other headphones that don't have this feature.
You get four different types of tip including traditional single and double flanged silicone ones and a familiar looking smooth coated foam type. However, there's another one that looks frankly scary. It's a variation on the double flanged silicone type but with firmer more pointed flanges. Unfortunately, none of the tips quite seemed to give a truly comfortable fit, at least to my ears. This seemed to be because the end of the driver enclosure is already very wide, leaving little room for the tips to adjust to the fit of your ear.
The best were the foam type that, unlike most normal foam tips, can just be inserted straight into the ear without pre-squashing the foam. They provided a decent level of noise isolation despite sitting quite shallow in the ear and they were also surprisingly comfortable considering their size. That said, they certainly don't compete in terms of noise isolation with the deeper-insertion tips from the likes of Shure and Westone and these earphones certainly aren't featherweight.
A pair of malleable over ear wire holders are included to keep the IE8s more firmly clasped to your ears. However, we didn't feel the need to use these as the 'phones felt perfectly secure without them. Besides which, I found they just ended up snagging on my long luscious locks, which will never do.
One thing we do particularly like about these earphones is the removable cable; a good tug on the connector at the base of each 'phone brings it away and you can then replace the standard 125cm one. Sennheiser hasn't gone quite so far as to include any alternative length cables but they are available to buy for a modest cost.
For those of you vaguely familiar with these earphones, you'll notice there's one aspect of them I haven't talked about yet and that's that they're adjustable. In a similar vein to the Sleek Audio SA6s, you can control the tone of the earphones to suit your own tastes. However, instead of replaceable treble tips and bass ports, Sennheiser has gone for a simpler option of a tiny dial on the side of each driver. Using a small screwdriver, or the included tool, you can turn the bass response from flat to, well, pounding!
Now when we first heard these earphones we had a bit of a play with this dial and generally had a good listen and came away fairly unimpressed. The bass even at it's lowest level was flappy and overpowering and seemed to come at the expense of top end clarity, while turning the dial up just extended this to near comic effect. A contender to the Shure SE530's crown, these certainly didn't seem to be.