Does the amine used to generate the enolate affect the selectivity of an Evans aldol reaction?

In an Evans aldol reaction, the enolate is typically generated by addition of a boron Lewis acid (e.g. $\ce{(n-Bu)2BOTf}$) and an amine, which acts as a weak base. I'd like to know whether there's any difference between 


1. Triisobutylamine, $\ce{(i-Bu)3N}$
2. *N*,*N*-Diisopropylethylamine (Hünig's base), $\ce{(i-Pr)2NEt}$
3. Triethylamine, $\ce{Et3N}$


in the selectivity of the enolate formation and subsequent aldol reaction. I'm thinking about the different $\mathrm pK\_\mathrm a$ values (1>2>3) and the different steric demand (1>2>3). Probably the base with the highest $\mathrm pK\_\mathrm a$ will be kinetically fastest. Also, the *cis*-enolate should be favoured as it avoids a destabilising *syn*-pentane interaction between the terminal methyl group and the auxiliary. However, do all of the bases lead to the same ratio of *cis*/*trans*-enolate formation (and hence diastereoselectivity in the subsequent aldol reaction)?


[![Generation of enolate for Evans aldol](https://i.stack.imgur.com/9NSCi.png)](https://i.stack.imgur.com/9NSCi.png)


