We used Kapa HI-FI and Phusion (both regular and HotStart) for cloning from cDNA, site-directed mutagenesis and general PCR to make >100 different plasmids. Phusion never introduced any mutations, the TM calculator is extremely accurate and in cases were primer-dimers were unavoidable the HotStart version did the job, for plasmids >10 kb KaPa was our only choice. It worked but introduced far more mutations than advertised and it is less effective because it always needs an initial gradient PCR.

I have no experience with the Invitrogen Taq.

In general I'd recommend to use Phusion as the workhorse and KaPa as a backup.

Have a look at the KOD Hotstart Kit from Merck/Novagen. You can get a free sample that lasts for a long time. The Kit is relatively inexpensive and contains dNTPs as well. As far as I remember that was not the case for Phusion (last time I used it >6 years ago).

We used Kapa HI-FI and Phusion (both regular and HotStart) for cloning from cDNA, site-directed mutagenesis and general PCR to make >100 different plasmids. Phusion never introduced any mutations, the TM calculator is extremely accurate and in cases were primer-dimers were unavoidable the HotStart version did the job, for plasmids >10 kb KaPa was our only choice. It worked but introduced far more mutations than advertised and it is less effective because it always needs an initial gradient PCR.

I have no experience with the Invitrogen Taq.

In general I'd recommend to use Phusion as the workhorse and KaPa as a backup.

I would recommend PfuUltra™ II Fusion HS DNA Polymerase from stratagene or Phusion. Both enzyme have very high fidelity and good productivity. They are especially suitable for template. PfuUltra™ II Fusion HS DNA Polymerase is also a hot star polymerase since it has a antibody block polymerase activity at lower temperature. I have used PfuUltra™ II Fusion HS DNA Polymerase for many templates larger than 10 kb for mutagenesis. It works almost every time. You do need to use minimum cycle number to avoid introduce mutation for very large template no matter which polymerase you are using.

check out this publication:

Optimal enzymes for amplifying sequencing libraries

Nature Methods 9, 10–11 (2012)

http://www.nature.com/nmeth/journal/v9/n1/full/nmeth.1814.html

To my experience, comparing KAPA HiFi HotStart, Phusion and Qiagen HotStar HiFidelity, KAPA was the best for amplicons less than 2.5 kb.

i compared KAPA HIFI, AccuPrime Pfx which had been our favorite, and NEB Q5 high fidelity to amplify a 3.3Kb fragment, using plasmid as template. in term of yield, KAPA is 2x more than Q5, whereas Pfx did not yield any. without knowing in our case the error rate,  KAPA is superior to Q5 in term of yield and specificity (lesser non specific products). my 5 cents. : )