I've got a MFJ-1796 and it has tuned OK as built, without any pre-installation pruning (no tuning tools when I was getting things together). A vertical di-pole, it has capacitance hats & coils top and bottom, so no requirement for radials.
Although I could tune for a useably low SWR on 80m, when actual performance is compared with a 130' OCF dipole the difference is very noticeable. Adjust for a comfortable audio level on an 80m contact, then switch to the OCF and the audio becomes uncomfortably louder. Differences at higher band freqs are nowhere nearly as noticeable. (This is just an observation, and not an issue as it is not advertised as covering 80m...)
If you do get a 1796, I'd recommend doing what I did and loosen each electrical connection (such as the bridges between coils and the capacitance hat components), coat with OxGard or Penetrox, and then re-tighten . I also sealed coax cut ends with a few coats of liquid electrical tape. This may be paranoia on my part, but so far, no issues.
Nick