Shop-Vac 12 gallon 5 horsepower contractor's series. Bought last year.
Works well but the hose is a weal link. I just duct taped the spot where it cracked due to wear. Didn't use it THAT much.
Good filter, easy to clean. Great suction. Blows, too. I use it to air dry the truck after drying with the microfiber towel. Sure gets rid of a lotta' water hiding behind trim pieces, etc.
Watch for sales on whatever brand. In the Omaha area the Rigid and Shop-Vac brands have numerous places to get extra parts, filters, etc.
You may want to note which brand offers the most extra goodies such as specialized nozzels, etc.
For truck drying I use a reducer that allows a narrower tube and nozzle to be used. Allows greater velocity that can be aimed better and allows me to stand far enough back I don't get sprayed with water droplets.
Also, consider the hose size. Smaller units usually have a smaller hose that limits usage. Larger units have the what? 2-inch or larger hose? Bigger is better!!!!!
Generally, reliability is likely similar in most ways. There's nothing too exotic about vacuum technology. My unit is a fairly large one but due to plastics it is easily portable...... within the yard. It's kinda big so may not be the best for those seeking portability.
If there's a Lowes and/or a Home Depot in your area check them out. In this area those stores have the best selection and a decent array of accessories.
As a plus, you can use your nifty powerful sucking/blowing device to clean the refrigerator's cooling coils and push the built-up lint out of the dryer exhaust hose..... preventing a possible fire.
I also use mine for cleaning the mice cages. The furry-faced critters revel in it. They come running to the hose, apparently enjoying the wild ride down the hose into the holding tank. When done cleaning I pop the top and see little rodent faces peering up at me, awaiting the hand that returned them to their home.
Such a handy device......