Low-Band vs VHF Hi-band
I'm going to chime in to respond to iamhere's comments, which have several inaccuracies
There is plenty of equipment made for low-band. Kenwood, Midland, Motorola and Vertex all make low-band mobiles.
As for base stations, the MSHP is using Daniel's Electronics exciters / receivers for all base stations. They work very well, and EVERY low-band remote base and repeater has been replaced in the last 3 years. In fact, the high powered transmitters, which are called Pecos, (made by Professional Electronics Company in the 90's) were originally driven by GE Master II's, with GE Master II receiver shelves. Those were also all replaced 4 years ago. In addition, the MSHP techs completely re-built all 18 Pecos in the state (9 were built in the early 90's, the other 9 are the backups, built in the early 70s). All high-voltage wiring was replaced, all connections re-done, and every transmitter gone through with a fine tooth comb. These transmitters are simple, and can be replaced with standard, off the shelf parts from RF Parts, Mouser Electronics, Digikey, and even Radio Shack. In fact, you can find the EXACT design of the amplifiers in the ARRL handbook. I forget which year, will have to try to dig that up. And yes, they really do make the 3,000-Watts they claim, even though most run between 1500 to 2300 Watts on a daily basis.
The current system is simple. It is reliable. Unlike the new VHF MoSWIN radio system, it doesn't rely on a master switch for the troops to talk to the tower sites and the consoles have not failed in the 15 years they have been in service.
The only problem with low-band is interference from outside sources, as some have stated. From in-car noise created by cheap computer components to electrical line noise from poor power company power lines, those are the two problems fought most often.
The Pyramid SVR-200 repeaters are not expensive compared to the Motorola 700 MHz DVR (digital vehicle repeaters) that will be installed in every patrol car. Pyramids cost roughly $1200 each while the DVR's $5,000. Same for mobiles - a Kenwood TK-690H runs about $1800 with the APX7500's about $7,000. The cost "con" is inaccurate.
Another pro no one has mentioned - low-band is exempt from the whole narrowbanding fiasco that everyone else is having to deal with.
The problem with low-band will be when the 3 biggest users abandon it - which I know California is #1, and I think Tennessee and Missouri are up near the top as well. If California were to abandon low-band, the manufacturing of low-band equipment would probably drop off dramatically. However, unlike Missouri, their consultants advised them it would be better for them to keep low-band and spend their money upgrading their current system. What has been discovered over the process the last three years is that most of the Missouri low-band antennas have been in service since the mid 60's to mid 70's, well past their expected life span. When replaced with new Comprod 532-70 style antennas, and replacing RG-8 feedline with 7/8" heliax, it is amazing how quickly dead spots have disappeared! Unfortunately, southern MIssouri antenna and feedline upgrades were never really completed due to timing with the new system. For those of you in Northern Missouri that listen to the scanner, you have heard the difference.
The Motorola / P25 Kool Aid is not served at my house . . .