Faster way of checking if application is running in AppleScript - applescript

Question

I'm using AppleScript in a program that should be responsive, but it seems like I'm hitting a bottleneck in checking if an app is running, which takes about half a second…is there a way to reduce this?
Here's what I'm doing currently:
if application "Finder" is running then
tell application "Finder" to activate
end if

Answer 1

This is what I am using (in this case for Word), which seems fast enough (less then 0.5 sec). Result is Appli_Launch = true or false :
tell application "System Events" to set Appli_Launch to exists (processes where name is "Microsoft Word")

Answer 2

Just adding a script how I use it. An idea is picked up from #pbell + if statement + python script.
This checks without lag if Mattermost app is running and then resizes its window.
#!/usr/bin/env python3
import subprocess
from subprocess import Popen, PIPE
def applescript_run():
script = """
tell application "System Events" to set Mattermost_app_is_running to exists (processes where name is "Mattermost")
if Mattermost_app_is_running then
tell application "System Events" to tell process "Mattermost"
set position of window 1 to {80, 0}
set size of window 1 to {1280, 800}
end tell
end if
"""
p = Popen(['osascript', '-'], stdin=PIPE, stdout=PIPE, stderr=PIPE, universal_newlines=True)
stdout, stderr = p.communicate(script)
print(applescript_run())