I wasn't impressed with the SG1 franchise's first direct-to-DVD endeavor. I would say The Ark of Truth easily makes the bottom third of SG1 two-parters. Instead of ratcheting up quality or plot, everything became more extreme and intense. Mitchell's lines were more O'Neill-like than ever. Mitchell and the IOA guy were both acting way over-the-top, in a bad way. There was some of the good in SG1 as well, in that some of the issues they had on the ship were of the "let's rethink this" variety instead of the standard Trek plot of "our first idea is great and has no problems whatsoever." But really...
The utter destruction of the Ori makes it worthwhile, provided they don't spend the next movie focusing on the political reconstruction of the ex-Ori universe like they did with the Jaffa. Seriously, I wouldn't put it past them.