snip
This may shock and dismay some people, but I agree with you Frank. A
102" stainless steel (or fiberglass) whip properly mounted will beat
shortened and loaded antennas any day.

Best location would be dead center on the roof, but with a cab-over
camper you can't do that permanently, although you could use a
mag-mount antenna and place it on top of the camper when you have it
onboard.
snip

A repost of a ACTUAL test:

The antennas:

108" SS whip
7 foot Firestik
5'4" X- Terminator double coil


The conditions of this test follow:

1. All connected to Hustler Quick disconnects
2. All used at 1.5 : 1 match or better
3. All tested with a constant tone, constant power transmitter
4. All used on a three magnet mount on the roof of a truck
5. All tested from a parked vehicle that never moved during each test
6. All tested within a very brief time period of each other (15 sec.)
7. All used a stationary Kenwood 940 receiver.
8. The 940 used a vertical beam free and clear of obstacles.
9. A video camera and a 31" television was used to display
a (31" S- METER) and record the results.

Thirteen mile free and clear of obstacles.

108" SS 5.2 s-units
Firestik 5.3 s-units
X-Term 5.4 s-units

Thirteen mile in the middle of the woods test

108" SS 3.3 s-units
Firestik 3.7 s-units
X-Term 3.9 s-units

Twenty four mile free and clear of obstacles.
108" SS .25 s-units
Firestik 1.3 s-units
X-Term 1.5 s-units