Since I'm changing to a new phone soon, I'm planning to use a 4G telco.

Which one has greatest value-for-money, (money VS speed of 4G) with 1GB high speed capacity max, and REPUTABLE unlimited data (aka so selow until LYN mobile loading time >1min or nothing at all)

No more unlimited data from any telco now. Highest is Maxis legacy plans - 10GB @ RM 99 mobile data but no longer offering to public.

1GB quota then with unlimited data in throttled speed, right?

for now, still either pick maxis or celcom, bcoz other telco not on par with m or c coverage

hopefully 2015 will see better 4g coverage by digi and u-mobile

and when YES and P1 ™ going roll out their LTE service

by that time only will be more choices

now good things is LTE smartphone getting cheaper, but those LTE usb/mifi/CPE still not price friendly.

Celcom First One Plan 5GB (free 5GB 60m Call 60sms) = the best plan of all telcos

No unlimited data since data now consider main income for Telco company.

Maxis quite stable in town area

U Mobile. 5gb + 5gb RM58 per month.

in term of LTE speed difference between diff telcos, which one is better ?

I feel that it's very subjective. Sometimes I got about 20Mbps but sometimes I got 9Mbps at different locations through M operator.

what a point super fast speed with a little quota ?
The cheapest 4G LTE price war goes to TMgo.

tmgo technically isnt 4g lte. it uses a wimax spectrum.