Well... if you decide to get one first of all use HackDaBox's excellent tutorial:http://www.hackdabox.com/spiderchip_squeeze.html
Don't even bother with the official SpiderChip instructions.
If you have an XBox 1.6b you should get a different chip, because the SpiderChip won't boot on a 1.6b out of the box - you'll have to install it into an older XBox, flash EvoX M8 Plus v16, and then move the chip into the 1.6b.
Don't know what version you have yet? Go here: http://www.xbox-scene.com/versions.php
The two main issues with the SpiderChip are getting the pogo pins to sit properly on the LPC port, and getting the wires through the via holes. If the vias are filled with lacquer you're going to have a tough time.
About a month ago I bought two SpiderChips to mod two XBox 1.6b's. I had no idea about any of the above until I came here... After borrowing an older Box to flash the chips, I got one working 100% with HackDaBox's squeeze method. I eventually gave up on the other one - I couldn't get one of the wires through a via hole and I didn't have the proper tools to clear the hole without risking killing the motherboard. My relative took it to his "modchip guy" who ended up doing an LPC rebuild on that XBox and then wiring the SpiderChip to it.
SpiderChip isn't the most recent modchip technology but it gets the job done... I'm a satisfied customer