Not growing that particular variety myself, but there's a thread about it in the tomato forum:

http://forums.gardenweb.com/forums/load/tomato/msg051043468825.html?44

Seems like it's a generally compact plant so probably nothing to worry about.

Oops, meant to make that clickable:

Porterhouse thread

A real winner. This is my first year for growing this tomato but it has been a huge success. The tomatoes are averaging 1 & 1/2 lbs and some reaching two lbs. It has been a sheer delight. Some tomatoes need more fertility than others and because of the size this seems to be the case. It sets well and does well even in our extreme heat and dry climate. My tomatoes are 5 feet tall--half way through the season.