"Slower and more tactical"? That sounds like a game that I could get into
The quick twitch, turn, jump combinations are a little too much for my nausea prone body to handle. It's one of the reasons I usually finish in the middle of the pack on Halo 2 on Live. Weird that held my own or actually ended up winning a few matches in the Halo 3 Beta.
I guess I keep this on my "wait and see" list till it's out or a demo releases. I've never played an Epic game till Gears. I both Love and Hate it at times.
When I say slower and more tactical, I do mean it as a relative to other similar games. Maybe "less manic" would be a better way of putting it. You don't have to be in the thick of pitched battle, though some maps insist on it. In some game types like VCTF you can hang back and support with vehicles, you can snipe at choke points, you can spend time reinforcing nodes (in Onslaught) and using turrets. The weapons themselves tend to offer more variation and imagination in how you use them. Maps can be "broken" by traversing them in unexpected ways.
You only have to look at the amount of emergent gameplay that ended up being integrated into normal play (such as the infamous "manta run" in VCTF) to see that the game rewards sneakyness and deviousness as well as good shooting skills. At the same time there are many "equaliser" weapons such as the redeemer, avril, ion cannon, tank, etc that allow less proficient players to stomp down on the single beserker opponent who has all the weapons and armour, and would otherwise slaughter you toe-to-toe. There is no "right" way to play, or "best" weapons to use.
Many's the time I've had the highest individual score in a VCTF game without touching the flag at all, just by playing defence and stopping the opposing team from taking our flag. Other times, I've seen teams with massive scores lose because they lost focus on the core task of stealing the other team's flag and got drawn into personal duels.
I'm not saying the game is set up to allow poor players to be as good as the best players, but it does allow the game to be played in different ways that allow the player to choose the techniques, movement, weapons (and how they are used), gametypes, vehicles that suit him best. I expect more of this in UT3, as Epic has stated on several occasions that they wanted UT3 to be more accessable to new and inexperienced players.
A good recommendation is to play the UT2K4 demo if you have a PC available. It will work on even quite modest machines by the standards of today's quad core multi-gig monsters. There are even still some demo servers around if you want to try it out online. You should find it has quite a different feel from other online shooter games.