Downgraded my Atheros Wireless Access Point

Well I figured an APU3 was a waste as a FreeBSD Wireless Access Point. So I found an old Checkpoint U5 Firewall I had used as a pfSense Wireless Access Point before learning FreeBSD and hostAP. I am pretty surprised how well it does. It gets 3 bars signal whereas my APU3 with Ubiquity SR71E WAP could only deliver 2 bars(In networkmgr).

Checkpoint U5 with CeleronM600@7W. 4 ports Intel Gigabyte LAN and one fxp0 for WAN. u5-500x500.JPG
This box is over 11 years old. Uses RJ45 console and Has SATA1 connector and SDCard
I would bet it is made by Lanner as the later FW7335,FW7341 models have the same layout.

My thought is that the old checkpoint U5 uses a MiniPCI slot and I have a real good radio there in the Mikrotik R52Hnd. It seems to be more powerful than my MiniPCIe slot SR71E.

So it leaves me wondering about signal strength.
The SR71E offers 400mw and R52Hnd offers 400mw

So Atheros hostAP signal strength from worst to best in my experience:
half card solutions like AR9280/9285
full card AR9280 like AR5BXB92
full card AR9380 AR5BXB112
full card AR9280 high power SR71E
MiniPCI AR9220 high power R52Hnd

I use a Terrawave Omni with high end pigtails for my Access Point Antenna.

Thoughts or Insight?
I also have a single channel MiniPCI card from Mikrotik I never tried. Offers 1600mw

What kind of results have you found?