I've just bought an ex-demo TTi TF930. It is a reciprocal counter with 10 digits and, importantly for me, goes down to 0.01Hz - most counters I've seen on e-bay start at around 10Hz. It also has no dead zone in counting (i.e. the counters aren't stopped when measurements are taken). It also has remote control via USB.
The reason I wanted the lower frequency was to allow me to connect a GPS 1pps whilst at the same time connecting an OCXO to the external reference. I can then adjust the external reference to get exactly 1Hz to 10 figures. A lazy approach to a GPS disciplined oscillator.
So far I'm happy with it. With the internal oscillator it reads 1.000 000 020Hz and it is very steady except when I regularly lose the satellites (I've not yet set up my outdoor antenna).
12 digits would be nice but the TF930 seems a good compromise between cheap 8 digit counters (which I felt wouldn't add much to the 6 digit one on my scope) and nice Agilent ones which even on their e-bay store are over £1000 (the TF930 as ex-demo cost me just under £200 ex VAT). I'd been looking on e-bay for a while and most 9 or more digit counters were quite old, didn't go down below about 10Hz or above a couple of hundred MHz and often were in the region of £140 to £200 anyway. And buying directly from TTi I get a years warranty and I like to support local (to me) companies though my spending budget will not make much difference to their turn-over!
The only negative (so far) is that the display is not backlit so needs good light, but this is partly to keep the power requirement down allowing the counter to be run from its internal rechargeable batteries or from the USB connector.