As Terry says, there is no Magic Machine............but there are many good systems and in the hands of SKILLED OPERATORS a portable or O/P machine is capable of equalling or outperforming a T/M.
Most TM owners will dispute this..........but, it's down to two criteria..........the operator and the product being used.............obviously, the correct, or best method of using products is critical.
This is not to say, that T/M's are a waste of money, which they clearly are not.........but, a poor T/M operator and there must be plenty, will not do as good a job, as a dedicated and highly competent, portable, or O/P operator.
Carpet cleaning is no different from the rest of the world, with 80% being average and 20% being, highly competent.................problem is, many assume they are better than they are and others undervalue themselves................but, " that's life "
Whatever you use, you should always be open to new ideas, or products.
If I was starting out, rather than backing out, I would probably want a powerfull portable, and a Prowler, or similar in the van.