Review: HTC myTouch 3G Slide
Browser
The browsing experience on the Slide is the same as on any other Android phone. The browser software does not appear to have been updated, and other than the substitution of T-Mobile's home page, you might not be able to tell it apart from other Android handsets.
You can use your finger to navigate around web pages directly on the screen or use the track pad on the front of the phone. There is a full list of settings that let you customize how the browser operates (such as enabling / disabling JavaScript, managing passwords and privacy).
In 3G areas, browsing speeds were inconsistent. At times, it was lightning quick, and at other times, molasses slow. When using Wi-Fi, it was consistently quick.
Customize
The Slide is an HTC Android phone. That means you can change nearly everything. In fact, T-Mobile and HTC have made a pretty big deal about the myTouch series devices being yours to customize as you please. For example, when you first boot the phone, it asks you a bunch of questions about how you plan to use the phone (mostly to check email, mostly to upload photos, etc.) and it then creates a user profile on the fly during set up. That's pretty cool.
The Slide also offers a bunch of different themes and modes which would appear to come from HTC's Sense UI. They can be customized at will, and the different profiles prioritize different applications depending on how you'll be using the device.
Obviously, with five home screens (expandable to 7 if you want!), the possibilities to personalize the phone are unlimited.