Learn what you want and need for what you'll be doing then decide what's best for you. The reason you'll see so many varying opinions is because we all run different business or have different perceptions of best.
If you need a truck mount right now, and you really don't know much about them, buy a popular name brand and have someone who knows about them look at it 1st, especially if you get a complicated machine. If you buy it with a van, do your due diligence and run it, drive it, and look underneath. There lots of pretty rust buckets out there, the guy who just painted it will usually tell you it's as good as it looks.
If you don't need it now, do research and really think about what your gonna need the truck to do, how your gonna fix it, how long you'll keep it, and how much your willing to spend on repairs over the course of the expected life. There are pros and cons to each truckmount and each van layout. Picking the wrong one of each or both can be frustrating or cause productivity issues.
There's lots to consider unless you can just afford the best whether you need it or not. If your cleaning commercial or ratholes heat can help alot. Big jobs or lots of tile cleaning need a big waste tank or a pumpout (if your want to use one). Some machine are reliable but produce low heat. Some are bad ass but finicky. Some are going to give better dry times. Some will be twice as expensive to run as another. Some will take up the whole van, some won't. You'll be able to fix some your self, some you won't want to. Some are easy for an inexperienced employee to run, some aren't. Some have very limited safety issues, some are dangerous if you leave the wand unattended without bypassing water. Some have proprietary parts, some don't. Some clean well at long distances, some are lame after 150ft. Some are loud, some are quite, some can be run quietly if needed. Some require you to keep your doors open, some you can lock it up. Some have saftey devises some don't. Some are easy to move (relatively) from one van to another some require the same model van or modifications. Some will leave you smelling like exhaust some won't at all. Some allow a van divider for the driver, some kinda don't. and on&on........................................
Will you take any less for that machine John? When can i come get it? 
