My TM HK416 is my first airsoft gun, so cannot really compare it to other makes. However, I think it is worth the price; it is well built, feels solid (although some may think it a bit heavy but that is where a sling helps), the recoil is fun and sounds great on full auto. It has plenty of rails for attachments.
Whilst the TM recoil magazines only come in two capacities, 82 BB low-cap (can switch them to real-cap 30 BB) or 500 BB high-cap. The 82 BB mags do not let the gun dry fire when empty as they hold the bolt back which is a useful feature.
Large enough battery space in the stock, and taking advice I swapped out the sopmod battery for a 7.4V LiPo with deans connectors.
If you like the HK trademarks, then some of the TM guns still have them, which is why they are not always advertised in stock.
Being 285-295fps means there are no issues with playing at any site, and there are third party parts/suppliers (i.e. Eagle6) to upgrade it. I have my hop set for 0.25g BB and it is accurate but does not have greatest distance.
Biggest decision is whether to buy the standard HK416D or the DEVGRU version.