The prepaid SIM is really a good alternative to spending money on data roam with your own SIM card. Top up options are plenty and can be made using credit/debit cards. Top up value can be used to purchase more data or passes.
I would say for RM10, this is really way cheaper than data roaming as most people use Social media more than downloads. Unless you are just there to run speedtests, a 300 MB for a 2 to 3 days stay is more than enough as you can still rely on the WIFI in hotels to upload your pictures or videos.
The SIM auto deactivates on the sixth day and a termination date is 50 days later. If you do not Top up through credit/debit/bank/topup card, the number will be deactivated. This SIM might not be suitable for frequent travellers as you will need to top up to extend the validity every RM 10 for an extension of 55 days. If not, this is definitely the card of choice for good coverage and speed.