dogecoin
coin for arbitrage between exchanges
i think so far only two of them ($LTC and $DOGE)
maybe we can include ripple $XRP on the list

But XRP is also using its own blockchain so we can make it compare with this coin. If we make this comparison totally fair than no doubt NANO has upper hand and a lot of benefits for long term holders.

Ripple is centralized.

XRB was renamed and now a new name is NANO

XRB, now NANO, created as a sand, and grown to be a giant.
The project has gone far journey to hit its all time high, which is out of expectations of all investors (I believe).

I still have the Nano wallet version 9. I opened it and it won't connect to the network. Why is that?

Because of version 9 not supported by the network already for a long time. Save SEED and download the latest wallet from https://nano.org/en/wallet

If you want the fastest access to your coins better use web wallets or download light wallet (Canoe or NanoVault) and import your saved SEED

Thanks, step_mike. You saved me a couple of Google searches. As for the lightwallets, no thanks as I prefer that I'm the only one who has the copy of the seed, encrypted or not - only maybe if I'm actively trading though.

Full synch can do from 4 hours till weeks or months. Better hardware (CPU, RAM, SSD, and network connection) faster synchronization. A completely different synchronization method will be applied from version 17 

The current number of blocks in the network can be viewed in any blockexplorer ( nanode.co nanocrawler.cc nanowat.ch )

it is important only for quick downloading of blocks, but a lot of time in synchronization is occupied by the process of validation of downloaded blocks, the speed of which is affected by the presence of an SSD disk and fast RAM