I have one and after some mods it's fantastic. My copy tracks so accurately that I consider it a mount rather than a camera tracker. It carrries my DSLRs, 60 and 76mm refractors and even the C6. I use it for visual as well as AP. I like to polar-align it properly for (unguided) deepsky shooting, for which I use Sharpcap's polar-align routine and a guide scope. I plan to run my 6D on Sharpcap to eliminate the extra optic (so that method might work for you too if you have a laptop). Alternatively, the solar noon method (if you're shooting from home) combined with accurate-ish altitude setting (for example with the help of an inclinometer app on your phone) will get you fairly well aligned as Leo says. In the field, under dark skies, being able to locate the SCP with binoculars or perhaps even the SGP's own little polar scope (that I haven't tried myself yet) is a skill worth having.
Apart from some minor niggles like how the clutch works, how the payload/counterweight bracket attaches, and the way it won't tell you how much battery charge(ing) you have left (to do), the stock version of the SGP had 2 bigger issues that drove me nuts and which I've since fixed. I felt they were critical for accurately pointing the polar axis and then the optic itself, i.e. actually using the thing as intended: the polar wedge and the declination 'axis'. I replaced the wedge with the
Wiliam Optics version and the Dec axis with an AliExpress sourced
geared pan head using ArcaSwiss standard dovetails. It is
so much better now.
Note - I also got the
WO Dec 'adaptor' initially, thinking it would be a similar level of improvement to their polar wedge. It's not. It's as infuriating to operate as the original. So either make do with the original Declination 'thingy', or get a geared or otherwise smoothly moveable and lockable panoramic head. I have to qualify this part by stating that I rarely use ball heads under the camera itself, so I need the Dec axis to move smoothly and predictably. A good ball head partly solves this issue too.
Can't comment on guiding, which is in RA only.
Having said all that, the mount will still work stock-standard - especially at the speeds and focal lengths you mention - but the more you use it, the longer the optics and the closer you want to get to exhausting the SGP's potential, the more you'll appreciate smoother and more accurate pointing.
