> The counterargument is that there's no other technically credible team in Bitcoin

You forgot the most important counterargument. That they _did_ move extremely fast on scalability. They released a masterpiece of engineering, SegWit, which doubles the blocksize, improves efficiency, enables future efficiency gains, and a laundry list of other improvements ... all while being a softfork. And, IIRC, that was all developed, tested, and released in _very_ short order.

True. Core's website has two good reads on SegWit for anyone interested:

https://bitcoincore.org/en/2016/01/26/segwit-benefits/

https://bitcoincore.org/en/2016/10/28/segwit-costs/

> That they _did_ move extremely fast on scalability.

Three years. People have been making issue tickets for three years about Bitcoin's block size.

"Core's" response was always to suggest an indirect fix to this by enabling SegWit.

>a masterpiece of engineering

Substantiate your claim.

>doubles the blocksize

Incorrect. 140% is the common number floated around.

>doubles the blocksize

140% block 'capacity' while using 400% more bandwidth. That is terribly inefficient.

>enables future efficiency gains

Substantiate your claims.

> and a laundry list of other improvements

Substantiate your claims.

>developed, tested, and released in _very_ short order.

Funny how Core halted development of Bitcoin for several years now up until now.

Now there is a frantic dash to get SegWit implemented as a fix to the block size issue even though it does not directly address it. What SegWit DOES directly affect though is the ability for Blockstream(Core) to roll out for-profit products that use Bitcoin as a settlement layer. This is the vision AXA[1] Strategic Investments and others have for Bitcoin and they are using their investments in Blockstream to make it happen.

[1] http://www.coindesk.com/investment-bank-axa-eyeing-bitcoin-f...

SegWit is in use by LiteCoin for a year already and the first proposal for Bitcoin was at least two years ago.

SegWit activated on Litecoin on May 10 this year.

Compared to changes of traditional currencies, two years is incredibly fast.

What? Central banks can change fundamental properties about a currency overnight. i.e. https://en.wikipedia.org/wiki/Swiss_franc#2011.E2.80.932014:...

Moving is a knob is a lot different than building a knob.

>as a result Ethereum is catching up and on the verge of overtaking Bitcoin

Ironically, scaling ethereum seems a lot dicier than scaling BTC.

Oh it is, Ethereum is considerably more complex and ambitious, and is starting to hit its scaling limits as well (like any time a popular ICO happens the network bogs down). And their solution, transition to Proof-of-Stake + Sharding, is also complex. That's going to be interesting. If there's a first flipping, there could later be counter-flippenings. But Vitalik is an excellent community manager and has so far managed to prevent a major schism like in Bitcoin.