If you speak to the people that sell Tablet PC's they will tell you that it is much quicker, more reliable and extremely cost effective to use them for this purpose - there again if you speak to the paper manufacturers they will probably tell you much the same thing. The truth of the matter is that it comes down to similar differences between using PC's and writing notes - PC's are good for somethings and so is a pen and paper.
I have carried out fairly extensive trials of both systems and the following points may help:
Advantages of Tablet PC's - Able to handle considerable amounts of information, the data can easily be downloaded to a central database, looks good to the customer and is easily turned into a finished document.
Disadvantages of Tablet PC's - Costly, easily breakable, difficult to carry around on an inspection, easily stolen, depends heavily on expert software, time consuming entering the data, when entering the data it is easy to miss problems, battery life can be a problem, not easy to amend expert software.
Advantages of a Paper Based System - Cheap, easy to carry around and easy to record findings.
Disadvantages of a Paper Based System - Can be lost, may require duplicate data entry if results entered into a PC.
Obviously, whichever system you use you will probably end up with a paper based system because someone will want to see a hard copy. My advice is that if you want to move to Tablet PC's you will need to have very good reasons to do so, not just what the seller would have you believe, because as you can see at present the disadvantages far outweigh the advantages.
Note: I have not outlined all the advantages and disadvantages for the two systems as readers will understand the general principles from using their own PC's. If anyone wants any additional information please get in contact.