At the risk of seeming a heretic, I thought I'd weigh in with a different perspective. I started peaking dishes around 1980 as a broadcast engineer, but nowadays I mostly just play with them as a hobby. I've experimented with rolling my bench SA out to a dish, remoting it via a laptop, using a STB receiver with a portable screen, making mechanical measurements with everything from a sighting compass to a theodolite, using a PC tuner to make engineering measurements with custom software/drivers and using simple meters, one that ostensibly measures the CNR of a specified signal (First Strike) and one that is simply stupid (Accutrac). I have seven motorized, five fixed and three toroid dishes with 56 LNB outputs, so I have plenty of opportunities to tweak.
To get this out of the way, I will say that if I was an installer I would seriously consider getting a sophisticated portable unit with a SA. Not that it would always be the best tool for the job, but given one cannot haul a lab's worth of equipment on the road, it is a practical compromise that packs a lot of troubleshooting power into a small case.
I've drooled over quite a number of brochures for portable satellite test equipment, but I've pretty much come to the conclusion that one doesn't need much for FTA alignment. Unless one is constantly changing a fixed dish amongst different positions, we normally set up a dish once. We may change LNBs and feeds or realign the dishes because of wind/other factors, but these tend to be much smaller tweaks on a largely existing setup. During the process of putting up my 15 dishes, I've been curious about what is the most efficient approach of doing this, both in terms of time and monetary outlay.
A few weeks ago I helped a friend install a 1.2m offset and a 2.3m prime-focus, both motorized from about 45W to 139W. I decided to take a minimalist approach. We exclusively used an Accutrac meter, except for one case where I verified the ID of a satellite at an extreme end of the arc using my First Strike. The latter wasn't necessary, but I wanted to check the range the actuator was covering. The initial alignments were done quickly and the only issue was making extremely fine adjustments from a mechanical perspective. After it was over I attempted to estimate the alignment accuracy over the arc from beamwidths and what the Accutrac read. Both estimates were better than 0.1 dB of pointing accuracy, but there was no direct way of checking. Regardless, my friend has since tried a variety of high FEC, high SR S2 feeds and easily got everything on C and Ku.
Yesterday I decided to realign my 3.0m, as it had been slightly nudged by a high wind storm. I took out only the Accutrac and misadjusted the dish alignment so I would have to start from scratch. In short order I had it tracking everything from about 37.5W to 139W and subsequently duplicated the measurements/estimates I had done at my friend's. They were all in the same neighborhood, better than 0.1 dB. I then checked these with my SA and using the custom PC software/tuner driver I wrote. It's not that easy to accurately make such measurements, but with a lot of integration I established that I was within 0.03 dB of the peak at the extremes and center of the arc. I doubt I could do better if I tried. It was actually much easier and quicker to do this with a simple meter than if I had used the SA, and the same would be true with the PC software/driver. The one caveat is I did not adjust skew. Past experience is the First Strike meter is capable of doing this, as is the PC tuner, SA and STB. My conclusion was that the quality of the adjustment is more dependent on technique and mechanical accuracy than on the cost of the measurement tools.
I do use my bench SA a lot for feed-hunting and to measure/troubleshoot overall and component performance. The crude spectrum analyzers in portable meters would be very poor substitutes for these functions. I've sunk less into a used, top-notch bench SA than I would have with a new, high-end portable tool. If money was no object, it would be nice to have both, but on a budget I'd rather spend the money on the bench unit with the savings from less expensive meters.