Brilliant.

Rating: 10/10 (24 July 2007)

WARNING, SPOILERS CONTAINED WITHIN.
Very much in the spirit of the original, and my observation is that the prime audience is people like myself who grew up on the Transformers. Almost everyone left the cinema with big grins on their faces (the only ones who didn't were the few ladies who had clearly been dragged by their significant other), I haven't seen such a contented cinema audience in such a long time.
I was surprised at the amount of comedy in the film as well, but it was well done comedy that didn't detract from the overall experience. There was some excellent comedic timing so it all worked rather splendidly, and they knocked the comedy on the head at the mid point when things started to get serious.
The CGI and action scenes are simply superb, second to none. The US armed forces in particular seem to have worked very hard with the cast and crew to make this a memorable film as well, I don't think I recall an action movie with such a large military involvement. That said there isn't an overuse of CG and it never comes across and being ladled on too thickly like a lot of recent films.
The autobots are just delightful, they've been characterised wonderfully. There are a few snippets of dialogue that will make anyone who grew up on the Transformers have a nostalgic giggle of delight. Peter Cullen's voice acting really makes Prime stand head and shoulders above the rest, although Megatron is superbly voiced. Starscream is actually fairly menacing rather than being all whiny and nasal, one of the only critiques I can level is that some of the decepticons all seem a bit "samey", almost like Stormtrooper syndrome. When the action kicks off it's hard to tell who's who whereas the autobots are all bright and colourful so it's easy to tell.
The movie ties up most of it's loose ends but sets the scene for the next film. My only major concern is that those who haven't really got an inkling about Transformers will miss a lot of the "feeling" of the film, but then I suppose you pay your money and take your chances.
Incidentally there is a glimmer of a love story but it's all hinted at and never really gets pushed to center stage. Although the movie has to kick off by focusing on Sam the movie is all about the Transformers, they really do take center stage when the scene setting has all been done. No gripes from me to be honest. In fact the love story is quite often used as the butt of the jokes, which suits me fine. One of my main concerns was that there would be a major love story arc messing up the ass kickery.
As a film I'd give it a definite 8.5-9 / 10. Because of the subject matter I'll plump for 10/10 because I'm hopelessly biased.