Summary: The DEH-1600 is the entry-level car stereo offered by Pioneer, and you can tell by looking at it, with its buttons for volume adjustment instead of a rotary knob, and a cd loading slot on the faceplate. But if you listen to this unit you might not be able to distinguish it from the top-of-the line models, because the DEH-1600 has the same amplifier as well as many audio adjustment control options. And with a price that is in the low $100's (in some cases less than $100!), the Pioneer DEH-1600 is, in my opinion, one of the best values you can find in car audio today.
I have a 1986 Honda Accord, and the Pioneer brands are extremely easy to install. In fact, all you need is a wiring harness, and since I already had that from my previous Pioneer cassette player that I replaced, all I had to do was remove the old unit, connect the wiring harness and antenna cable to the new unit, and place it in the slot. This literally took a couple minutes. Although ease of installation depends on your vehicle, I have never heard of Pioneer units being difficult to install, so this should not be a concern if you are considering this brand.
The DEH-1600 has a fairly nice and simple design. The cd loading slot is on the top of the faceplate with small illumination lights located on the edges of the slot to help you insert a cd when it's dark. All of the buttons are illuminated as well, which is a good thing since some of them are very small. The volume control buttons are on the left while other adjustment buttons are on the right, with radio station preset tuning buttons on the bottom. The LCD display is large and well-lit - I never have a problem reading it in the sunlight. Unlike the rest of Pioneer's models, the DEH-1600 does not have a rotary volume control knob, which makes it look a little cheap as well as a 'little' more difficult to use. But any cosmetic drawbacks are negated by its excellent sound quality.
Pioneer has the same MOSFET 50w x 4, 22w RMS power amp in all of their models, so the DEH-1600 literally sounds just as good as their more expensive units. When I first listened to it, I was amazed at how much better it sounds compared to my old stereo (which I was very happy with), not just the stronger bass and treble, but the better clarity and separation. It has 6 stored equalizer curves, including POWERFUL and SUPER BASS, and you can also make your own adjustments and store your settings. It has Loudness adjustment, as well as Front Image Enhancer (FIE) and Source level adjustment (SLA). The FIE cuts the mid and high range frequencies from your rear speakers, which means that you get just your bass from those speakers. The SLA allows you to adjust the volume level between the cd and radio, so when you insert a cd, you can make sure the volume is about the same as that of the radio you were just listening to, and vice versa. All of these audio adjustment settings, along with the strong amp, makes the DEH-1600 an excellent performer.
The DEH-1600 has the Supertuner IIID (like its other models), which I find has great radio reception. You can store up to 18 FM stations and 6 AM stations. It also has the LOCAL/BSM function. The LOCAL allows you to adjust the unit so it only tunes in to the stronger broadcast stations, and the BSM automatically finds and tunes into the 6 strongest stations - something I only do when I drive out of town.
The cd player also plays back CD-R and CD-RW discs, and after trying both formats, the unit played them without any problems. You can also pause a track, play them in random order, and repeat. I don't do any offroad driving, but I've gone over some rough roads as well as speed bumps and the cd player never skipped. I previously had a Pioneer unit, and in my experience their quality has been excellent.
The DEH-1600 has a strong amp, great sound quality, great radio reception, and plays CD-R/RW's. It is Pioneer's entry-level unit, but only in terms of appearance. If you can get past that, this model is an excellent value.