The polemaster absolutely is great. I use it. But it does need a view of Polaris and surrounding stars.
The ioptron iPolar looks to be the same except they perform a plate solve and will get you polar aligned without looking at Polaris. A friend of mine uses it and it works fantastic also. Now I believe it is available to be mounted on any telescope mount such as our exos2 mounts, but have not myself done it. Suggest to research that a bit and add it to your trade space analysis.
Wes, Southport NC
EXos2-GT PMC-8, iExos 100
ES ED 127, 10" LX200GPS+wedge, Astro-Tech 8" Newt, ETX-90, 60mm no-name guide scope ~ 260mm FL
Polemaster, Orion ST-80 and SAG, ZWO 290MM, D5300 astro modified
Nina, Bootcamped Mac Mini control computer, RDP to iMAC
110 amp hour lead acid deep discharge battery for field power
Electrical Engineer, Retired