Want so ask sifu-sifu sekalian ... assume budget 1k

For now, should I get Huawei B618-65d or the newer B818 ? Or other model ?

Plan to use with my existing Maxis sim card. Currently using low-end 4G LTE/MiFi , can right ?

Is B818 fully compatible and higher spec as compared to B618 ? How about the upcoming 5G in Malaysia ?

Thanks

What are the current big quota/unlimited package as hotspot/tether ?

Standalone
TM Unifi Air - RM79/month (sim only)
DiGi i150 - RM150/month

Package
Maxis One Prime broadband/unlimited - RM89 + RM98 + + + expensive yo!

Call Celcom, ask them to reset/change your location, you may need to provide your Ipoh address so they can lock it to the telco towers there. You can only do this once/twice per year. Hope you are not going back to Subang Jaya or else where very soon.

Yes, but doesn't matter, still works. A lot of people scared about firmware upgrade lock, but firmware upgrade can disable in settings.

Yes, the 5GHz wifi is very weak or maybe my walls are thick. Anyway I don't have B618 or other equivalent stronger WiFi AP to compare.
The 2.4GHz also weaker compared to my older AP
Too bad currently my area is congested, so far cannot get >80Mbps d/l even at non-peak hour, but I have not tried 2am-7am.
Also a lot of interference due to urban area, SINR always between -1 and 2 only. RSRP, RSRQ and RSSI those are green. I wonder how some people can get SINR >10
I'm only about 300-400m direct distance from two towers that I regularly able to connect. I've been spending some time using CellMapper to map my area.
Lock B3+B7 Maxis

Stability and strength wise, definitely better than my previous lower grade modems.

Use other WiFi AP plug into B818 as modem since you have stronger one. Disable WiFi in B818

Yes, B818 definitely can "tarik" signal compared to my cheap modem by 2x-4x especially with 4G+ 2CA

I never own B618 before, but from what I learn/read, B818 performance is equivalent or 10% better from few who has done the comparison.

Current day price wise for 4G/LTE modems from what I saw:
B818-263 about RM600 +/-
B618-22 Celcom lock about RM200-300
B618-65 Unifi Air about RM400-600+
B618-65 m0dded price inflated to RM750-1k due to TM change to ZTE modem

There is a better one for the upcoming 5G : H112 / H122 price RM1.2k up.

Not just this device. There are other home-based modems that has 4G SIM slots. Buy a SIM extender cable so you can easily swap the SIM between your modem and mobile.
Otherwise, depending on your telco package, you can request additional multi-sim for data only. Need to pay RM10-15 extra monthly. It will share the data from your existing line.

Those are 1A output for 525/310/etc.
B618/818/+++ all requires 2A.
Some will use power delivery powerbank with minimum 18W output.

I'm still searching for a proper 2A output or something I can piggyback into fuse-box. Insufficient power may cause brownout and intermittent modem reboot. However, there are some who says they have been using it without issue for years, etc.

I'm not going to risk my unit yet ...

Sell the B618. Get proper mesh wifi

Quite a lot of technicalities to get it right.
- para pointing to the correct telco tower
- para height - as high as possible
- dual antenna cable type and length = signal degrade/loss
- connectors

Have you manually check to set external antenna to On in your B618 (192.168.8.1) ?

Could be congested as well. Try 1am-6am comparison.

I believe you use hmanager to check the SINR, RSRQ, RQRP and twist/turn the antenna while on the roof to get the strongest signal ?

Just wondering are you in city urban/suburban or in kampung area/plantation ?

Most of the time (if not all the time), para or dual-LDPA will perform better than the internal antennas.
- bigger antenna = stronger dBi/dBm
- externally located

Also if cheap/low-end cable and the length is >=15m will cause a lot of signal loss also, which may equal to not performing better.
Recommended are LMR400, 200, RG6, 8, 58 (if I remember correctly)
Also the connectors if too many joins. Or if cable<->connector joins are poor quality will cause a lot of signal loss also.

There is a B618 FB group you can join and ask also, many experts there.