I like my 3D printed Windsurfer twin reflectors, only $25. They utilize the same principle of of DBS and FPVLR, using a directional antenna for greater distance, but you have to point the antennas at the bird during flight. Windsurfer gets me out over 2 miles, which is almost the limit battery-wise (with no battery mods). Even at 2mi I don't have much time to take many photos or video once I get there, so anything with a longer distance capability isn't of much use without the battery mod, which I'm interested in (too many batteries to charge). I had the FPVLR antenna kit and Sunhans amps on another drone. Yes, this combination does work, but now you have to charge yet another battery all the time to power the two amps, which is a problem if you forget to charge. The worse part is the RC won't fit in most cases unless you remove the antenna assembly. The DBS mod unit is the most convenient for removal, give the nice clip mechanism they include. DBS also seems less fragile vs. FPLVR, and ergonomically easier to store away. However, if you ever turn on the RC accidentally before attaching the antenna wires back to the RC, you can blow your RF circuitry in the RC. So don't forget it!
I bought the twin pair of Windsurfer reflectors. Having two of them separated (versus the once piece version) make it easier to store them when I don't use them, which is about half the time. However, if I take off on a flight with them not installed, then I start getting a weak signal, it takes me about 20 seconds to grab them and slip them over the antennas, hassle free. Besides being easy to store in most any case or backpack, I don't have to worry about charging a battery for an amp. I also don't have the risk of accidentally turning on my RC without the antenna wires connected. There are a lot of virtues of the Windsurfer setup, but the DB Mod and FPLVR setups with amps will certainly go farther. I just find all that H/W a pain to deal with, too cumbersome IMO. With Windsurfer I can opt to have an omni-directional control of the bird sitting down in my lawn chair without having to move around to point the RC with nearby flights, less than 1000'. With DBS or FPVLR you're forced to ALWAYS point the RC toward the bird, you can't go back to omni-directional, as possible with Windsurfer. Convenient, flexible, safer (from blowing RF circuitry), and reasonably effective, not to mention inexpensive.