If there's no one forcing you to use svn, then you should probably use git, since git can interoperate with svn (which means, technically, you could use git while the people you are working with use svn; that's probably too much trouble though).
As for XCode integration, git has none but it is not too hard to get git working using some keystrokes in XCode. I wrote some scripts that will do it for the most frequently used git commands and placed them in user scripts. Here are two examples:
git initialize
#!/bin/sh
#
# This script initializes a git repository and adds all the elements
# of the project directory to the repository
# Set the basic variables of the script.
project_directory=`osascript << APPLESCRIPT
tell application "Xcode"
set mypath to the project directory of project 1
set mypath to the POSIX path of mypath as string
end tell
APPLESCRIPT`
cd $project_directory
# create the git project configuration files
cat << EOF > .gitignore
.gitignore
.DS_Store
.gitattributes
build/*
EOF
cat << EOF > .gitattributes
*.pbxproj -crlf -diff -merge
EOF
/usr/local/bin/git init
/usr/local/bin/git add *
git add
#!/bin/sh
#
# This script does a git adds a file of the user's choosing
# to the git repository.
# Set the basic variables of the script.
project_directory=`osascript << APPLESCRIPT
tell application "Xcode"
set mypath to the project directory of project 1
set mypath to the POSIX path of mypath as string
end tell
APPLESCRIPT`
files_to_add=`%%%{PBXUtilityScriptsPath}%%%/AskUserForExistingFileDialog "Add files"`
cd $project_directory
/usr/local/bin/git add $files_to_add
You can see a pattern here that will allow you to quickly write up the others. Inside the "user scripts" dialogue, you can assign key sequences to the commands. I find that in everyday use I rarely need to go to the command line to use git.