The Tiger 100 is a far more stable board than the Tiger 133, and the BX chipset reliably outperforms the VIA Apollo Pro 133A. (See AnandTech's own articles on this point.) The fact that the Tiger 100 is far more popular than the Tiger 133 over at
http://2cpu.com (especially among their experienced users and their moderators) should also tell you a lot; see 2cpu.com's review of both boards on their site. Yes, you can overclock 700E's in the Tiger 100. The main disadvantages of the Tiger 100 are the following:
1. No native ATA/66 support. (But you can add a Promise Ultra 66 for about $25.)
2. AGP is 2x max. (Not a big difference in actual use.)
3. There is no 1/2 AGP divider, so if you run at 133 FSB, your video card has to handle being overclocked. This isn't a problem for most newer video cards; see AnandTech's "BX 133 Video Guide" for more info.
4. The "EB" Coppermines aren't supported on this board, which I verified the hard way. (But you can overclock other Coppermines up to a 133 MHz FSB if they can handle it.)
5. Memory speed is always the same as FSB speed.
Unless any of these is a show stopper for you, I'd go with the Tiger 100.