David, I have an LP12 and I can reassure you that the Reference Table *will* do everything you expected of it.
However, some points to note:
(1) LP12s take a bit of time to settle if they have been moved; my LP12 (a mongrel '91 plinth/Cirkus/Akito (soon to be Aro )/Asaka/Lingo with some minor modifications) takes a few days to settle down again to its best performance.
(2) When purchasing the Reference Table, I trust you ordered the circular level? If not, find an accurate spirit level and ensure that the platter is level. A cheap plastic level is not sensitive enough. You may find that, in order to level the platter, the glass may end of fractionally 'off-level' - this is OK (IMHO); the crucial thing is the platter:stylus versus gravity; we want the platter to be orthogonal to gravity.
(3) Mana tables themselves can take a day or two (or more, if you have a phase 2+ setup) to settle - after this time, check to see that the table has settled and that the ring is still there.
(4) How tightly did you do up the nuts on the spikes? They should be just a bit tighter than finger-tight; use the supplied Allen key, and (having tightened the nuts as much as you can with your fingers only) use the Allen key with your little finger (which is too weak to allow you to overtighten) - this, IME, ensures the correct tightness.
(5) Ensure that you haven't knocked the bias or counterweight whilst setting it up; perhaps your cartridge is just mistracking a little. You didn't move the LP12 with the counterweight in place? On some of the more sensitive arms, this can occasionally cause some damage (if what I am told is true).
Hope this helps; email JW at Mana if you still have difficulties.
John (from QS to Phase 5 Mana in 6 months. Ouch - the wallet didnae ken what hit et!)