1) The Thiel cabinets. The cabinet fronts slope outward to improve timing and the fronts curve away to mitigate corner effects. They are very well braced and heavy to reduce flexing. Downsides: Passive radiator (doesn't bother me much most of the time but a lot of people are not crazy about that), terminals are hard to work with (you need to tilt the speaker up which requires a second person for the larger units), and you have to be careful about the relatively flimsy wood skirt at the bottom (don't use even a padded dolly on the larger units). They are attractive with excellent fit and finish.
2) The Montana cabinets are built like a brick &%@#house. Very, very heavy with a sextagonal (sp?)vs. rectangular design to help reduce standing waves. Woofers are moved outward from the tweeters in a less elegant fashion than the Thiels, but the effect is the same. Felt is used around the tweeters to reduce reflection effects. Did I mention that they are very, very heavy to reduce resonance? Their larger speakers have wheels for easy moving (at least on hardwood) and allow for spikes so the wheels can be lifted from the surface. Very easy access to terminals.
2) The Montana cabinets are built like a brick &%@#house. Very, very heavy with a sextagonal (sp?)vs. rectangular design to help reduce standing waves. Woofers are moved outward from the tweeters in a less elegant fashion than the Thiels, but the effect is the same. Felt is used around the tweeters to reduce reflection effects. Did I mention that they are very, very heavy to reduce resonance? Their larger speakers have wheels for easy moving (at least on hardwood) and allow for spikes so the wheels can be lifted from the surface. Very easy access to terminals.