Good Morning,
I'm looking at getting a scanner having not owned one for about fifteen years. A lot has changed since then. I live in SE Harris County now and I'm thinking about either a BCD996P2 or a BCD 436HP. If anyone has either of these scanners and can let me know how well (or not) they work with the TxWARN system in Harris County, I would appreciate it!
As already noted, Simulcast will be an issue no matter where you are in Harris count. Multiple simulcast sites in use, in various areas, for both Harris county & smaller towns, as well as Houston itself.
Read more about Simulcast in the Wiki:
Simulcast digital distortion - The RadioReference Wiki
The 436HP is marginally better than the P2 scanners (325P2, 996P2), but it will struggle as well. If used solely at a fixed location, there are a few work-arounds for simulcast that occasionally work. Such as use a directional antenna, use 'less' antenna (even so far as only using a
paper clip), use the attenuator, and a few others. In some cases, these might work, especially if you are very close to one of the actual transmit sites. But all bets are off the minute you walk out the door & start moving.
If you still want to try the 996P2 or 436HP, be sure to purchase from a dealer that does not heavily penalize you for returns (in case the scanner simply cannot handle simulcast at your location). The SDS series scanners are, of course, more expensive than the two models you mention, but they are designed to work well in simulcast conditions.
I would also avoid paying the dealer to program your scanner, no matter what model you decide to use. The database scanners, such as the 436HP/536HP, as well as the SDS100 and SDS200, can be programmed by the purchaser, or simply use location, range, and service types to specify what you want to hear. There are a lot of helpful threads here on RadioReference, as well as Wiki pages & YouTube videos on programming your scanner.The dealers charge $60 and up for one county, with charges exceeding $100 if you want two or more.
Also, don't pay for the dealer to install any upgrades, such as DMR NXDN. They'll charge you $75 or more for something you can do for much less yourself, by dealing direct with Uniden. I would also suggest not adding either of the upgrades until you receive the scanner & are confident it will do what you want, as being free from any issues. If you bought, say, a 436HP, and immediately purchased the DMR upgrade, but then needed to return it, you would not be able to recoup the upgrade costs.