I don't claim to be an expert, but I chose the Fujitsu Lifebook T series T4215 (the latest is the T4220). Reason 1: I can put a second battery in the DVD modular bay giving me about 4 real hours of working time. This was the most important criteria for me. If I plug in while driving, and I don't keep it on all the time I can get a full days work out of one set of batteries. Reason 2: It has the fastest chips to run Xactimate, Dragon Naturally Speaking, mapping software, etc. Others offer a lower voltage, but slower chip, but don't get much more battery time. Reason 3: Fujitsu makes a custom fit "bump case" that allows me to scope/write while I walk through the house. I wanted a way to carry the tablet even when I am climbing roofs. Reason 4: Fujitsu offers a useable indoor/outdoor screen - so I can work almost in any lighting condition. Other things I like: small easy to pack docking station, built-in SD card slot (for downloading photos immediately), Fujitsu's reputation, 4.5 lbs even with the second battery. Xactimate 25 runs easily on this machine.